You need to execute a bit of scripts on the server side to make them searchable
First, you need to determine your center of the map. Then add markers / location to the map and save their server lat / lng values. When someone enters a zip code / zip code, you need to use the Google Maps geocoding API service to get the lat / lng value of the entered value, use it as the center and then calculate the distance using the haversin formula to show the nearest locations.
Geocoding API Link
Haversine Link Formula
thanks
source share