@Muzzyelk, If all spacing is the same (as indicated in your screenshot) you can use the below formula to return your desired results. May want to first plug it in on the results, as a Formula Numeric field, so that you can visually see the logic. Then move it to the criteria subtab to exclude the not needed results:
CASE WHEN SUBSTR({arrangement-geo-field-id}, INSTR( {arrangement-geo-field-id}, ':') -1) != SUBSTR({customer-geo-field-id}, INSTR( {customer-geo-field-id}, ':') -1) THEN 1 ELSE 0 END
Hope this helps!!