Actually, it will be different folders for every user, sorry for the confusion.
There is a virtual directory that every user has access to, however, they have their own folders in that directory:
domain.com/virtual_directory/user_1
domain.com/virtual_directory/user_2
etc.
I simply want each folder calculated within Plesk for the respective user. As it is now, each users folder is left out of his disk space usage calculation within Plesk.