What @gwootton proposes could work but you would end-up with multiple metadata library definitions that all have the same metadata name and libref. For any user with some sort of admin rights that provide read access to more than one of these library definitions the result will still be "random" which library metadata definition will get picked. I consider such duplicates in SAS Metadata as not recommended and it created issues for me in the past for example when using SAS DI Studio.
What you could do instead:
1. Define the library in metadata once with a dummy pathname and as pre-assigned (pre-assigned so SAS DIS doesn't create the libname statement when deploying the code).
2. Add logic to the the usermods autoexec where you issue a libname statement with a path depending on the user who invokes the SAS session. You could of course in this autoexec syntax also query SAS Metadata (or OS) to determine to which group a user belongs and then use a path based on group membership and not individual user.
The libname statement in the autoexec will overwrite the libname defined in SAS Metadata with the same libref.