Add a group to another group
This feature requires turning on Google Groups for Business.
When you want to create a group with many members, you can save time by adding other groups to the list, rather than adding members individually. For example, if you’ve already created groups that include all of the members you want to add, then you can add these groups to your existing group.
A benefit of using nested groups is that messages you post to the parent group are also posted to the child groups, assuming the child group's posting permissions allow it.
If you need to add or remove a member from multiple groups, just edit the smaller group to which the member belongs. All of the larger groups are updated automatically.
Note: You can only add groups that are in the same domain as the larger group.
How posting permissions work
If you add a group to an existing group, the child group inherits the membership of the parent group you add it to, but does not inherit the parent group's permissions. However, if the larger group allows "all members of the group" to post, then members of the child group can also post to the parent group.
If you add groups to another group, you need to set the Post permission for these groups to All organization members. Otherwise, messages posted to the parent group may not be received by members of the child groups.
To add a group to an existing group:
Sign in using your administrator account (does not end in @gmail.com).
Click the name of the group you want to modify.
Click Add users to group .
Enter the name of the group you want to add to the selected group.
Note: Multiple group names must be separated with commas.