Complex sentence: He starred with Mariette Hartley in the 1966-67 season comedy series "The Hero", in which he played TV star Sam Garret, who in turn starred on a fictional series as Jed Clayton, U.S. Marshal.
Split into simpler sentences: He starred with Mariette Hartley in the 1966-67 season comedy series "The Hero", in which he played TV star Sam Garret. Garrett had starred in a fictional series as Jed Clayton, U.S. Marshal.