Groupings
From MoodleDocs
Template:Moodle 1.9In Moodle 1.9 onwards, a set of groups may be organised into a grouping.
To use groupings, the feature must be enabled by checking the enablegroupings box in Administration > Miscellaneous > Experimental. This will result in a groupings tab appearing on the Groups page.
In the centre of the groupings page is a "Create grouping" button.