Management groups are used to effectively manage all your Azure subscriptions in an organizational or environment-based hierarchy.
However, if you have many subscriptions under an extensive management group structure (management groups can be up to six levels deep with many child management groups), it is sometimes difficult to keep a good overview.
Luckily, you can get an overview of the current management group structure by using Azure Security Center.
How to get a management group overview
Logon to the Azure Portal and click on Security Center in the sidebar.
In the Security Center dashboard blade, select Security Policy under the POLICY & COMPLIANCE section.
You can now see the number of management groups and subscriptions, as well as a representation of your management group structure in a tree view on the Policy management screen.
Hope it helps!