Hi Arthur! (NO SPAMMER!)
You are looking at Geo proximity feature for Map.
I can assist you with this. Have a look on my large mapping portfolio :)
To differentiate this real proposal from spammers, please click on LAST ✅ mark here -->
Above action will help you to see meaningful proposals at top when you are filtering through all the proposals.
Before we go ahead, we need to first discuss certain parameters :
1 - What is current web map ? Leaflet, Google , Mapbox ?
2 - What is current back-end serving data to map ?
3 - I am assuming we are dealing with mapping over web, right ?
Thanks,
Dhrumil