That is very tricky. Have you though how this would happen. Each arduino will have it's own unique map because it is a unique position in the topology. It will also be impossible to do this with a simple broadcast message system, you will need at least a pair of input / output communication links per arduino.
We have Arduinos linked up via '4052' multiplexers.
Each Arduino listens to four other Arduinos in turn, and sends to 'their' multiplexers as well. Listening in works well, we still have to see whether it works bi-directionally.
I'll try to have the Arduino network broadcast information on individual connections over time (like 'i'm no. 1337 and i'm next to you!', 'i'm no. 42 and i'm connected to no. 1337!').This way, they could have at least a map of their immediate neighbourhood.
A custom-made modeler app will collect this information and adapt the representation of the assembly: