Post Processing for selective geometry?

Is it somehow possible to assign a Post Processing Volume Material to a selective group of geometry?

Thank you for any thoughts, or ideas.

This is generally achieved with the “custom depth” stencil. If you search for that term, you can find some great materials. This applies to post process materials specifically.
Other types of post processing (such as motion blur) may have a different process, or might not allow per object control depending on the specific effect.

Thank you very much. But how can you use that PP Material just on a selected geometry?
Any video tuts for that?