It’s currently not supported out of the box and would require some C++ coding. You can however implement a kind of jumping behavior with navlinks and triggers. Navigation links tells AI “you can traverse this segment”, so if you place a link between two platforms AI will find a path as expected. You just need to take care of the jumping part, and you can “fake” it by placing a trigger on the link start that will make AI move to the other end.
Making “AI move” could be done in couple of ways: you can simply teleport your AI, matinee-animate him, or set his physics to Flying and just let him continue (should work, but I haven’t tried it :D). If using the flying option don’t forget to turn Walking back on once “jump” is done 
If you’re interested in proper way of solving this in C++ just let me know.