It’s not folder based, so a different kind of beast.
If you want both “tags” (well, machine-learning based classification) and recursive folders with filtering, Sononymis a good choice.
Not free though, but you can pick it up for half price next week
Oh, and I made a tool that integrates Sononym more closely with Renoise, too.
Thank you, Danoise! Definitly checking out Sononym - looks really amazing, and with your tool maybe it is exactly what I am looking for.