I have modified the individual category pages
to add a search bar and an optional tag filtering system for the specific category you're browsing.
Many people often ask us why we don't add more refined categories to the site as they are struggling to find specifics (like armour for males in the armour category, or building mods with quests, etc.) and the answer is generally that we don't want hundreds of categories and sub-categories cluttering the site. Using the tagging system you can really drill-down and refine your search to the specifics that you are looking for within categories.
I'm hoping users will find this system helpful. The system is newly made and only tested by me so the changes have only been applied to TESNexus right now. I'll be porting this over to the other sites after a bit of feedback from the users here on TESNexus, so feel free to provide constructive feedback on this update.