Except for the continent of origin, there are almost no restrictions on how you route yourself within a continent. You can use a city as a hub, if you want to, and pass through as many times as your segment total for that continent allows allows. (4 or 6 free, two more for a price, 20 total for the entire trip.) There are some nits about only one cross-country in US and OZ, and only one "long" trip LHR-far away-LHR.

As noted above, if you start at BNE, once you return to BNE you'll not be allowed to fly any further segments. Also, in continent of origin they limit stopovers to two - other places there's no limit, just the segment count. Stopovers are 24 hrs or more, so you can do some quick stops if it pleases you.