Are there any players who have won an NCAA basketball championship while playing for two different teams?
No player has ever won NCAA basketball championships with multiple teams.
The player who came closest to achieving this is Bob Bender. He was on the undefeated 1976 Indiana team that won the national championship, and he was also on the 1978 Duke team that lost to Kentucky in the title game.
Wikipedia says Bob Bender is the only college basketball player to reach the NCAA championship game for two different teams:
Bender has the distinction of being the only individual to play on two different teams in two different NCAA Championship games.
It’s only happened once in college basketball back in 2005. His freshman season, Brandon McGarity won a NCCAA Div II National Championship in 2002 with Central Bible College in Springfield, Missouri and he won a 2nd NCCAA Div II National Championship hire’s senior season in 2005 with Southeastern University in Lakeland, Florida.