You can specify a sub organization created in your Google account to discover the user accounts that are added in that sub organization, and then add them automatically to a user-defined subclient.
From the navigation pane, click Protect > Applications > G Suite.
The G Suite apps page appears.
Click an app.
The app page appears.Click an app.
The app page appears.
In the Subclients section, click the user-defined subclient to add user accounts for.
The user-defined subclient page appears.
In the Content section, click Manage.
The Subclient content dialog box appears.
Click Add rule.
The Add google groups dialog box appears.
Select one or more Google sub organizations from which you want to add user accounts to the subclient.
In the Subclient content dialog box, click Save.
What to Do Next
Run a backup operation on the user-defined subclient to back up the user accounts that are automatically added to the subclient based on the regular expressions that you configured. For instructions, see Backing Up Gmail and Google Drive.