The way we’ve been reading it (there is some ambiguity) it appears BYU would get into the CCG in the 3-way tie, and would have the 2-way tiebreaker against both KSU and ISU.
Either KSU or ISU would win the 3-way tiebreaker, then BYU would win the 2-way tiebreaker against the whichever of them didn’t win the 3-way tiebreaker.
There are 2 things in the tie-breaker that are a little ambiguous:
First, the 2-way tie-breaker with ISU would come down to “ Win percentage against the next highest placed common opponent in the
standings.” I assume this would refer to KSU, which we would win, but some have postulated that the word “next” could exclude KSU because it would refer to the next team down the rankings.
Second, if BYU loses to Houston or Kansas, there is a chance they may allow two teams to advance simultaneously from the 3-way tie-breaker (ISU/KSU), but even in that scenario I still think it would revert back to the 2-way tiebreaker with the loser of those 2 against BYU.