Latter, or even both.
But still, since it's highly likely that there won't be 2nd division for each league, managerial experience won't be as rich as it could be. That one and only 2nd division would most likely have to remain tied to the league in which we'd start our campaign (and perhaps fixed Segunda tied to Liga BBVA, if certain licensing rumors are going to come true)  ... hence there would be a lot of leagues without relegations/promotions, pretty much as it now in BAL mode. IMO, it would be total nonsense if that one division 2 would just follow us around as we change clubs and leagues