Navigate to your LEO unit. From the Administration menu select Unit administration > Users > Groups.
Click on the 'Groupings' tab.
Locate the grouping you would like to add your group or groups to. Click on the third icon in the 'Edit' column, it looks like two people. This is the 'Show groups in grouping' icon.
In the next screen that opens, there will be two columns: one which represents the 'Existing members' of your current grouping, and one which lists the 'Potential members'. Click on a group in the right hand column to select it, then click on the blue 'Add' button. Repeat this step as necessary until you have added all of the appropriate groups to your grouping.
You are able to add multiple groups to your groupings at a time by holding down the 'control' button (PC) or the 'Command' key (Mac) and clicking on all of the groups you want to add to your grouping. All of the groups you have selected by will be highlighted in blue. You can then add them to your grouping by clicking on the 'Add' button.
You can remove a group from your grouping by clicking on the name of the group in the left hand column and then clicking on 'Remove'.