Finally, I was able to correctly replicate the comparison between the same field by creating the islands tables.
The problem now arises from a request made by the client at the last moment. This field has a hierarchy and you want to be able to select any field. For example: [Region], [Country] and [State] and the power of the United States vs Europe.
Try to create three different islands, also add the missing fields to each island table and it does not give me the result you have to give me.