subfolders under "all site files"


I have an elgg installed for an organisation. Since technically all of them knows each other, I installed a be_tom plugin where everyone becomes a friend of everybody upon login. I installed also the folder plugin (file_tree) to organize their files. So far so good. Now with their files growing, they are having a harder time to find a file in 'all site files'. Is there another way aside from filtering the files as pictures, videos, documents, etc? I am thinking like having a pseudo-subfolders they can create under the 'all site files' to get their files organize. How can this be solved? Any suggestions, comments and remarks are highly appreciated.

Thank you very much.

Brother Brix