You can create cluster groups for the DocumentDB clusters that you want to back up.
From the navigation pane, go to Protect > Databases.
The Instances page appears.
On the Instances tab, from the View list beside Instances, select Cloud DB.
The Instances page for cloud databases appears.
Click the instance.
The instance page appears.
In the Cluster groups section, click Create cluster group.
The Create cluster group dialog box appears.
In the Name box, type a name for the cluster group.
From the Plan list, select the server plan to use for the backups.
In the Backup content section, select the clusters or the instances that you want to back up. You can select complete regions and instances within regions.