Frankly, I'm surprised it has taken so long for this to happen. In the early to mid-'70s
Bill Cosby did three films with Sidney Poitier (who also directed) called
Uptown Saturday Night,
Let's Do It Again, and
A Piece of the Action. The films aren't exactly related in a narrative sense - they feature different characters, in different cities - but are clearly related in that they feature Cosby, Poitier ...