This can be done from Location Hierarchy (LH), you can simply delete that location (location a), once you delete it then upload the same map file again and go back to LH and you will see it there in the main page (not under any parent location)
If you don’t see it you can simply refresh the page or delete the cache (I see problems sometimes when doing that from Google Chrome so I prefer Firefox when doing that)
Once you see it in LH then you can go to the top level and choose “Edit Group” and choose that new location to include it. (if you can’t see the new location as available location after clicking Edit Group that’s mean you need to go up one level and so on until you see it in one of the top levels)
Keep repeating the above step until you place this location under the parent location you need.
If there are rules associated with this location (location a) or portals, then you will not be able to delete them until you remove them.
When deleting a location you will get this warning: Deleting this location will remove all child locations underneath this location and will erase all analytics data associated and its child location(s)
