To add members:
On the sidebar menu, tap Groups.
Open the group.
Tap More, then tap Members.
In the bottom bar, tap .
In the list of Contacts, select the people and groups you want to add.
Alternatively, search for users or groups to add.
Note: You can't add outside users (people outside your company) to a group. Outside users' names appear in purple text, and they have icons () after their names.
To remove members: