It can do that yes.
On the clean access server configuration page (through the manager), go to "filter" , "Roles", "bandwidth"
You can set bandwidth restriction per role (so a kind of group of users). You can also chose to share the limitation between all the clients currently connected in that group, or to give that limitation to each client.
Example if you restrict to 100Kb/s the user role "marketing", then you can either have the whole marketing department limited to 100kb/s regardless of the number of marketing users connected or say that each marketing employee is restricted to 100kb/s.
I hope this answers.
Nicolas