How to customize Contact Map popup on clicking on icons?
When you select Google as the map provider, I assume the Map Contact shows up.
Ensure that When you select GoogleCityOnly, you also retain the Google Map API Key. The code checks for the presence of both a mapping provider and a mapAPIKey before displaying the Map Contact link
If you want to "modify" the code to avoid the Map API key for now, check: CRM/Contact/Selector.php and search for mapAPIKey