Complex sentence: Curson started training Brazilian jiu-jitsu (BJJ) in 1995 under Rickson Gracie until his Blue belt, and eventually received his Black belt under Rigan Machado.
Split into simpler sentences: Curson started training Brazilian jiu-jitsu (BJJ) in 1995 under Rickson Gracie receiving his Blue belt. He received his Black belt under Rigan Machado.