Very straightforward suggestion, just a regular Medium Earth map copy-pasted 3 times to make 3 Earths.
The Earths should be arranged either horizontally or vertically, your choice, but it must have the same connections i.e. Russia and Canada are connected to Antartica, Americas and Asia are connected via Hawaii, etc.
I made a thread a few months ago about this, but it's too old to get bumped.
[Map Suggestion} Triple Medium Earth: 9/19/2013 23:09:49