As much as I love digging around in the Grid edit of S3PE (where I bruteforced most of my knowledge about anything), making hiders and recategorising the contents of Build/Buy and CAS has been synonymous with tedious one-at-a-time edits for too long. I have a lot of respect for the existing tutorials and EA hiders that have been shared. Today, I would like to share the method to make edits to entire sets of items at a time.

If you've never used the programs listed below, setup might take 5+ minutes.
The actual process of hiding any number of items at a time with the right setup takes a few clicks and you're done.

Requirements
S3PE
Batch Resource Editor
Notepad++
S3OC for EA items.
CC Magic for creating Collections.
The XML template set attached to this post.

Template XMLs
TEMPLATE_OBJD_Hider.xml - The one used in this tutorial.
TEMPLATE_CASP_Hider.xml - All references to ‘OBJD’ in this tutorial are interchangeable with ‘CASP’ when used with this xml instead, to hide CAS items.
TEMPLATE_OBJK_FoodMakerify.xml - Requires Arsil's GenericFoodMaker . Interchange ‘OBJD’ with ‘OBJK’ and use with this xml to replace the script of objects with the food maker script. ie. use on a set of decor appliances.
EXAMPLE_ToiletsBeGone.xml - A practice / proof of concept .xml that you can immediately run through BatchResourceEditor to create a package that hides all of the Base Game toilets.

Process Index

• (CC) Merge Packages
• (CC) Export OBJD to File and to Package
• (EA) Obtain IDs in S3OC
• 'Copy to Path'
• Paste and Vertical Select
• Paste into XML
• Run Batch Resource Editor

Hiding an Entire Set
For the purposes of this tutorial, I will be using AroundtheSims3's McDonald's set. I love clutter! I love custom food morsels!
Then you get ingame and...

... there's a chicken nugget in with your small appliances ft. a baby bottle I forgot to remove when taking screenshots.

And the most familiar CC burden, Misc Decor becoming a lawless wasteland where opening this section at all becomes increasingly impossible the more CC you use.

Exporting OBJD
My example will begin with a file of merged CC you can learn to create by skipping to the green header.
If you are editing EA items, scroll down and start from EA Instance IDs.

Open a merged package in S3PE, which should only contain things you want to hide. Click 'Tag' if the resources aren't already sorted by type.
Scroll down to find the OBJDs, click the first one, scroll to the last, hold Shift and click the last. Every OBJD in the package should be selected.

Right click, Export to file, choose a new EMPTY folder. If you're hiding a hundred objects, this is going to create 100 loose files. Keep them separate from anything else.
Without unselecting the OBJDs, right click again, and this time Export to package. Save this somewhere else and name it appropriately. I called mine HIDERS_MCDONALDS.

This is how I arrange mine. A dedicated HIDERS folder, an OBJD folder for the exported files, and the package created by S3PE. Keeping things tidy will help avoid confusion.

Copy to Path
The next step requires my deepest thanks to C. Dark for helping me over at NRAAS, because before this method I used to select each OBJD one by one and copy paste the Instance to a document. I never would have shared this tutorial without being able to completely cut out the tedium that only my stubborn brickhead would put up with just for a tidy catalog.

Open the folder you exported all of the OBJD to as files. CTRL+A to select them all. Hold Shift while right clicking for Copy as path to appear in the menu.
The hotkey to do this might vary depending on your operating system.

EA Instance IDs
When you are working with hiding EA content, you only need the ID- BatchResourceEditor reads the game files directly. You can:

1. Find the object in S3OC and right click > Copy Resource Key, paste into a text document.
2. If you are hiding all of a similar object, you can use S3OC’s Tools > Search to find all resources sharing a word (ie. Sculpture, afHair, etc), select all the ones you want to include in a hider, and Export to Package. Follow the same steps above to Export to File and continue from the steps below. The package itself doesn't need to be saved.

Paste and Vertical Select
Open Notepad++ and paste.

It will look something like this, but with more mess listing your harddrive and user name. I removed this for readability.
Regular Notepad, Wordpad, etc will NOT work. Why? Because the next step is to vertical select.
The final string of numbers and letters is the Instance ID. Click the space between the _ and the instance in the first row. Hold ALT and click and drag to the final character of the instance in the last row.
This will select only the Instances, as shown. The hotkey might be Shift+ALT for some.
Copy the selection.

You can, and should, delete all those loose OBJD from the folder when you're done.

Paste into XML
Now we need to open an XML designed for Batch Resource Editor by SimsMX in Notepad++. This is a great tool that almost became unusable due to the example XML originally provided with the mod not being archived by Simlogical Luckily for you, I reverse-engineered one enough to include a set of templates with this post. You can use 7ZIP after downloading to get the XML out.

The hider template is called TEMPLATE_OBJD_Hider.xml and contains 50 blank nodes with the 0x bit of the instance filled in and the OBJD node for being hidden from Build/Buy. If you are editing less than 50 items, you can remove the extras. If you are editing more, you can select a chunk and copy paste until you have enough.

Click after the 0x in the first GUID node. Paste your vertical list.

They should fill the nodes like this- it's better to have more than you need so nothing breaks the other tags.
Save as so you don't overwrite the template. I named mine HIDERS_MCDONALDS again. Matching names is optional- Batch Resource Editor will overwrite if they're matching or make a new package if they're not. End result is the same.

Batch Resource Editor
It's time to open Batch Resource Editor, and it's incredibly important to adjust the settings first by clicking the ?

In the menu that appears, tick Ignore Store Content and untick Ignore Custom Content.
You will notice that the tool will detect your game and expansions (or need help doing so if you install to a custom location.) All of this can be ignored for now, but for future reference you can know that it's possible to use this tool to edit EA items. Except Into the Future, which was released after support for this tool ended.
The most important step is to edit the file path for Custom Content to point to the folder your hider package is in. This way, the tool doesn't have to look through every piece of CC you have to find what you're editing.
Close out of the settings when you're done.

Select the XML prepared earlier, HIDERS_MCDONALDS.xml in this case, as the Input XML.
Select a folder you want your hider to drop as the Output Folder. I choose the same folder I'm working in so it replaces the package I already made.
Edits to EA items can be installed to Mods > Packages.
Edits to CC should be installed to Mods > Overrides.

That's it! Regardless of how many IDs you included, the tool just removed all of their Build/Buy flags.

Now your catalog looks like this,

...and optionally all of the CC is neat and tidy in its own Collection folder.


Using Collections to Access Hidden Objects
Merging CC and making Collections isn't really related to making CC hiders, even if it's absolutely required if you still want to place that CC.
We all have different skill levels with modifying the game, and I didn't want to scare away people who haven't used CC Magic starting with instructions on how to use it.

In CC Magic's Collections tab, click Add, give your collection a name, and select an icon. There is quite a limited selection here, but you can change it ingame if you wish.
Don't close the program or Refresh before building a set with the new collection or it will disappear.

In the Sets tab, make a set for the CC you are hiding. CC Magic grabs any package or sims3pack you leave in your The Sims 3 > Downloads and displays it under Default. Move the CC from there to the set you made for it.

Select the Collection dropdown menu and click the one you made for it. If it doesn't show, click any other set and back.
Click Rebuild and a merged file of the CC will be created in Mods > Cache > Sets > [YourSetName] (the ModBuild0 package inside is what I began this tutorial with) and a collection file will be created in Collections > User .


Finally, if you launch the game with CC Magic make sure to move the set you just made from Disabled Sets to Enabled Sets under the Configurations tab.

Recategorization?
My personal thing is hiding CC, but Batch Resource Editor was designed primarily to change the categories of EA objects and clothes (and CC).
The original thread is archived here and SimsMX gives many examples of nodes you can use.

For example, you can replace the number used in the ClothingCategory CASP node to make other changes. Edit a CASP in S3PE > Grid to find the number that represents your preferred categories.
I'll include more XMLs for this as I playtest what can be changed.

Final Words
Another incredible thanks to C. Dark, whose method of getting multiple instance IDs made this possible. I used to copy them one by one. And before that, many of us unticked all of the flags in S3PE per item...
Thank you to Peter and Inge for S3PE, Granthes for CC Magic, and SimsMX for Batch Resource Editor. I didn't make any of the functionality used here, just resurrected it.
Thank you for including this in the tutorial section

Nice tutorial, I am here too 🙂
Will check this out later, but do I understand this right?
It's for hiding CC items in the general objects categories, so you need to create a collection for them in CC Magic (I have it),
but how should this work with CAS items? In CAS there is no collection area.
You mentioned CAS in the title.

It's good to see you!
I've mentioned in the last section that due to CAS not having collections, hiding should only be used on items you don't want to use. In the same way one might use MasterController's Blacklist to hide them ingame.
It's also possible to change categories without messing with visibility.
Otherwise, all of the same steps translate for removing or recategorising CASParts.

For reference,
All mentions of OBJD would instead be the CASPs in the package and the final node in the XML would have to be modified.

would replace the <OBJD> node. That specific bit includes not valid for random nor visible in CAS.

These can be found in S3PE's data grid for a CASP, changing the flags under ClothingCategory change the main number. Different combinations could be used to enable for maternity, outerwear, etc- the categories that tend to be missing from older CC and EA items. I could include more XMLs tailored for different purposes over time, I just don't know what is desired.

Sadly, because Batch Resource Editor was hosted on Simlogical it's a bit of trial and error. Only the first page of discussion was archived and SimsMX hasn't been around since 2013.
If more specific flags can be changed, they'd have to be found through testing. It's all a little bit of necromancy sometimes

UPDATE:
Now that I have a feel for how to structure tutorials, I've made some pretty significant changes to this one.
The tutorial is now about 50% slimmer but 50% denser

• Major brevity edits for simplification.
• Included steps for EA items.
• Reformatted for clearer understanding.
• Single XML replaced with an entire set of templates and one example. All playtested for functionality.

Enjoy!