I made this tool for myself and a bunch of friends who wanted to split a larger map (with objects all over SA) into multiple maps easily, without having to open the .map file while looking for x and y coordinates and manually filtering potentially hundreds of objects (that's obviously a no-go).
Figured that maybe some of you might find this useful. Usage is pretty straightforward, added some information in the tool to help you out. Hope it helps!
https://github.com/marty000123/Marty-s-MTA-SA-Map-Cut-Tool