Locate the group that you want to be the parent group. You can browse or search
for groups.
Click the appropriate group name to expand the details pane.
Click the Groups tab.
Do one of the following:
If the parent group doesn’t have any nested groups, click + Add groups
manually. Locate the group that you want to nest, and then
click the + icon..
If the parent group already has nested groups, click the pencil icon and then click
Add/remove groups. Locate the group that you want
to nest, and then click the + icon.
The + icon changes to a check mark when the
group has been added.