I would really like to see a way to filter through different kinds of items in your inventory/on the ground, so that when you have a mountain of things, you can sort through all your things by catagories (ha, see what I did there?)
Isn’t that the advanced inventory menu?
It sounds like the key you are looking for is ‘/’
If not, though, is there any improvements you’d like to see made to the advanced inventory management screen? Personally, I’d like the ability to split a large stack with it… important, for instance, in the case of an immovably huge pile of ammo.