Complex sentence: His late father (born in Jeju-do, South Korea), worked as a doctor; his mother (born in Sinuiju, North Korea) worked as a nutritionist at a hospital her husband owned.
Split into simpler sentences: His late father born in Jeju-do, South Korea worked as a doctor. And his mother who was born in Sinuiju, North Korea, worked as a nutritionist at a hospital where her husband owned.