my take on this is look into techniques used in computer games. i remember when GTA3 came out, and its most epic achievement was loading free inter-map transit. still very few games use this but it's a graph theory algorithm. this is the kind of thing you need to automatically, and quickly partition a map of related data. you need metrics of proximity and some kind of parameters for partitioning the map to fit the compute you need to do. it's not hard. but it may take a while to wrap your head around it. but graphs at high node count are N! style compute cost. so it only takes like 3 or 4 deep and you are practically at infinity as far as even the most powerful computers can do in milliseconds.