[legofarley]

The closest I've been able to get with OOTP is to set up a league association between all your individual leagues. Then set it to have the top four or eight teams in each league and it will set up a new playoff bracket.

Here's an example. I have four major leagues, each with two subleagues, who do not play each other in the regular season. For me I have a North America league, South America, Europe, and Asia/Pacific. After each leagues' championship (world series in MLB), the top four teams in each league then get placed into the league association playoffs (WBC) and they battle it out for the best team in the world.