The way that I understand it they would only need to beat Iowa once. I think it used to be a double elimination until the end but looking at the B1G site, basically the winner of the "losers' bracket" is playing to get back to the final game to face the sole undefeated team left in a 1 game championship.
I still cannot believe they let a 4-0 lead in the 9th vs Iowa get away, that is insane! Regardless of how they finish today they have probably secured a #2 seed in a regional, which is phenomenal compared to where they stood at the start of May.
Beat MSU! then beat Iowa! Go Bucks!!