Try using the google maps widget from the appstore https://appstore.home.mendix.com/link/app/48911/Mendix/Google-maps
That is not available out-of-the box AFAIK. That would require two things, a way to select cities in google maps (maybe this) and adapt that changes to the google maps widget.
See also my answer to this related question which was asked a while back:
Hope it helps in knowing the (im)possibilities with Google Maps currently.