In Solo: A Star Wars Story, at the planet Mimban, Han gets thrown into a pit where he was supposed to get eaten by a beast tied in chains, who turns out to be Chewbacca.
In Revenge of the Sith, Chewbacca was shown at Kashyyyk when Yoda leaves.
However, how did Chewbacca end up on the planet Mimban? This isn't explained in the movie, but is there any in or out-of-universe explanation for it?