Wayne Selden and Bobby Portis seem to have a bit of chemistry together. It was only this one game and it was only four assists, but all inter-teammate chemistry has to start somewhere. And it’s a good idea in general to attempt to build chemistry with Portis, because he has clearly demonstrated in the past what he does to players with whom he doesn’t have chemistry: he punches them so hard that they have to go to the hospital. Selden diming up Portis is just a self-defense mechanism on Selden’s end to ensure that his jawbones and cheekbones stay in one piece.
Selden also hit Robin Lopez with three nice passes, so there might be some budding chemistry there as well. Selden’s motivations for this are a little bit hazier since Lopez has not been known to hospitalize his own teammates. The simple explanation is that Selden is just trying to be a good teammate by getting his teammates involved, but I don’t like simple explanations. I prefer presumptuous and demonstrably incorrect explanations.