Creating a library based on the root

Blender has a ton of brushes, and I'd like to create my own brush library. I realized I can't duplicate the main brush directory. Even if I duplicate brushes and create a subdirectory, I can't simply drag and drop brushes into it.

I also noticed that I can't right-click a subdirectory tab (like in browsers) and have to search through the Resource Library, which is a bit confusing. Even if you delete a directory, it will not be deleted from the panel, only in the Asset Browser