SAS Studio does not currently offer a way to hide folders in the directory tree that a user doesn't have access to because the file navigation interface functions in the same manner as Windows Explorer where users can see folders even if they cannot access them. As a workaround, you can set the custom root path to each individual user's directory using the <userid> token in the path (ex. set the custom root path to G:\Data\Users\<userid>). Then if users also need to access other directories on the G:\ drive, create global folder shortcuts to each of the directories every user needs access to. This will effectively "hide" the other user directories that users do not have access to in G:\Data\Users\ from the SAS Studio interface.