Way to link custom data using campaign editor?

I have been trying to link object editor and import manager data between maps by using the campaign editor, but for some reason it doesn't seem to work. I am probably doing something wrong, but i have double checked many things over and over with no result. I added the map to the campaign, and I even chose the campaign file for the external custom data source in map preferences for the map, but yet still, when i change something in either the campaign editor's object editor, or the map's object editor, and save both the campaign file and the map, they both remain independent, having their own seperate data.

If you know of any way to solve my problem, help would be much appreciated.