Changing the Administration Group Hierarchy
Organizations are rarely static--new lines of business may be added or perhaps groups are reorganized due to organizational expansion. To accommodate these changes, you may need to make changes to the existing administration group hierarchy.
Beginning with Enterprise Manager 12c Release 12.1.0.3, you can change the administration group hierarchy without having to rebuild the entire hierarchy. You can easily perform administration group alterations such as adding more groups to each hierarchy level, merging two or more groups, or adding/deleting entire hierarchy levels. All of these operations can be performed from the Hierarchy page.

Note:
After making any change to the administration group hierarchy, click Update to save your changes.