There are four ways to add users to a group.
Add an Existing User
Select the group you would like to add the user to.
Click "Add Person" button from the middle of the screen.
All users in the top organization will be in the drop down. Type in their name, select it, and click add.
Invite New Users Via Email
Complete the same process as adding an existing user from above.
Type in their email from the drop down and click add.
Users will show up on the team in grey font until they accept the invitation. You can revoke an invitation any time by clicking on their name and clicking revoke.
Add Users to a New Team
Create a New Team by clicking the New Team button in the middle of the screen. Make sure to click the group or team on the lefthand side that you want your new team to be in.
Name the team.
If you have a large group of users you would like to add, contact your Customer Success Rep to implement this action.