Complex sentence: Nelson attended the University of Florida, where he was a member of Florida Blue Key, and the Beta Theta Pi social fraternity, before transferring to Yale University, where he was a member of the Book and Snake secret society.
Split into simpler sentences: Nelson attended the University of Florida, where he was a member of Florida Blue Key, and the Beta Theta Pi social fraternity. He transferred to Yale University, where he was a member of the Book and Snake secret society.