How to find opponent coordinates

How can I find the coordinates of another alliance in my kingdom?

There is no certain way to find coordinates of alliances that do not want to be found, except for just looking through the complete map. If you don't mind other people knowing that you are looking you can ask in kingdom chat if anyone knows, often alliances have enemies that know where they are. If you find people from the alliance not in their hive, you might keep an eye on them, they might still join rallies, exchange resources etc and you can track from footsteps.