Complex sentence: He met ex-fiancé Nicki Minaj while he started rapping in the same hip hop group as her in the early 2000's in Brooklyn, New York City they started dating and working together outside of the group.
Split into simpler sentences: He met ex-fiancé Nicki Minaj while he started rapping in the same hip hop group as her in the early 2000's in Brooklyn, New York City. They started dating and working together outside of the group.