I'm not so sure about metadata but you can make them a course where they all have teacher access. They can drag and drop into the course and then when they are in their own courses they can go to Server files and bring in to their courses the files they want.
This could be a solution, thanks. We are using this feature already, They all have acces to eachother's courses. I was just hoping for a repository where we could keep a different order in the files.