Once groups are created, it’s time to assign (enroll) students in the groups. Go to the Manage Groups page from Course Admin. Be sure to select the Category from the drop down you want to work on and then select Enroll Users from the drop down:
From this page, you can enroll users in one or more groups.
Note: if you set up the assignment, discussion topic or locker in the Create Groups tool, access will begin immediately. If you created these items before the groups, you will need to set up Conditional Release on the items you wish to filter.