"The ACC team's opponent in a given year will be the highest-ranked available team from the SEC, Big Ten, and Notre Dame, subject to several constraints: the SEC and Big Ten champions are always excluded, and when an SEC and/or Big Ten team qualifies for the College Football Playoff, the next available team would also be excluded from participating in the Orange Bowl due to contractual obligations with the Sugar Bowl and Rose Bowl, respectively. Also, should a highest-ranked team create a rematch with the ACC team, the Orange Bowl has the option of passing over that team for the next-highest ranked team among the Big Ten, SEC, and Notre Dame, again subject to the noted constraints. Rankings are based on the College Football Playoff committee's rankings. ESPN holds the television rights for 12 years as well."
WikipediaThe Orange Bowl is an annual American college football bowl game played in the Miami metropolitan area. It has been played annually since January 1, 1935, making it, along with the Sugar Bowl and the Sun Bowl, the second-oldest bowl game in the country, behind the Rose Bowl (first played 1902, played annually since 1916). The Orange Bowl is one of the New Year's Six, the top bowl games for the NCAA Division I Football Bowl Subdivision.
https://en.wikipedia.org/wiki/Orange_Bowl#Conference_tie-ins