You can delete a destination group, as required. Before you delete it, ensure that it does not have any destinations added to it.
Click on Destinations link available in the left sidebar. The sub-links appear as below.
Click on All Destination Groups link. The All Destination Groups page appears.
Note: You cannot delete a destination group if any destination is added to it. Before you delete a non-empty group, assign a different destination group to its destination so that it is empty when you want to delete it.
Locate the target destination group in the list.
In Action column, click on the Delete button. The backend system asks you confirm if you want to delete it. Click on Ok to confirm it.