Interesting and useful but I think you misunderstood.
I live in small town A. There is another small town B next to my small town. I would like to retrieve this small town B (presumably using the Maxmind geoip city database). None of the default functions provide something like this since and since there isn't a completely obvious relationship how small town A and B are stored in the huge ass geoip city database, it's not an obvious solution.
(In reality there is a relationship in the way A and B are stored but it's a very annoying one to program, so essentially... anybody want to share their code for Maxmind... or is there another solution completely unrelated to Maxmind for this.)