Hi Ben,
Every single Tag can be placed on a different or the same as other layers. Tags’ layer-‘membership’ has not to be the same as the objects they belong to.
Tags can be named, and a name-system can contain several fragments, so each Tag can be found with the search in different group settings.
Tags can be selected with the option given in the Object Manager, have a look at the icons in the upper right corner.
While creating a Selection Object is typically used with Objects, it can contain Tags only, but it needs an Object to work, which can be then deleted from the list. Selection Object can be created over and over again with different sets.
The Take System can specify individual setups where some Tags are enabled and other not and all on or off as well.
Does anything of this sounds like a something you would like to explore, then please let me know, I happy to share more about each option of course.
Cheers