Complex sentence: She started becoming interested in K-pop by listening to artists such as BoA--in a 2016 documentary, Tiffany emphasized that BoA was the reason why she would later on moved to South Korea.
Split into simpler sentences: She started becoming interested in K-pop by listening to artists such as BoA. In a 2016 documentary, Tiffany emphasized that BoA was the reason why she would later on moved to South Korea.