Your understanding is incorrect. Do a lot more browsing on this board, come up with an itinerary, then use the validation tool and come back and ask for advice.

In short and in general, one cannot return to the continent in which one starts and then leave again. Additionally, one must travel around the world in only one general direction, west or east. To come as close as possible to what you want, you might consider buying a ticket to either BKK or CMB from Australia and originating/purchasing your xONEx there. That way you could travel in Asia, Europe, NA, then return home for awhile before returning ot Asia and starting a new xONEx.