File/Directory Permissions Question
I'm trying to get acquainted with Linux after dealing with Windows for decades, but here's a question regarding file/directory permissions:
I have a shared directory and members of 2 groups need to access it. Group A should have read-only access, Group B should have read-write access, and Groups C+ should have no access whatsoever.
In Windows this would be a breeze to set up the group permissions accordingly. From what I understand about Linux though, I can specify one set of permissions for the owner, another set of permissions for a specified group, and then a third set of permissions for everyone else. This makes setting 3 different group access policies seemingly impossible.
What would be the best way to control access to this folder in the manner I need to do so? The folder is shared via Samba (if that provides any additional functionality).