I use P3DO Explorer to quickly browse runtime libraries.  I used to use it to sort and categorize content--like I'd put all the figures in a "People" folder, but a specific characters clothing into a separate folder like M4 clothing.  The problem with this is that if you use Daz Studio it often has problems finding content that's been reorganized, then you  have to play "Go Fish" to try and find it--so I've given up on that--while Poser seems to have little difficulty linking up files, it's still not worth it if you end up getting "cannot find file" error messages.  Use the search features in Poser and Daz Studio to find things based on key words, it works remarkably well.  When you get a lot of content in one library start another one.  I  have a runtime for Daz gen 1 &2 figures, one for Daz 3rd generations, and Daz 4th generation content as well 3rd party library for stuff that does not tie into Daz products.  It does get confusing and complicated.

There are some applications that make it possible to categorize stuff without actually moving their physical location, you might want to try one of these.