Complex sentence: Gopalakrishnan had seen Varma's work in his second film as a cinematographer, "Olavum Theeravum" (1970), and when he decided to work on "Swayamvaram", Gopalakrishnan approached Varma with the script.
Split into simpler sentences: Gopalakrishnan had seen Varma's work in his second film as a cinematographer, "Olavum Theeravum" (1970). So when he decided to work on "Swayamvaram", Gopalakrishnan approached Varma with the script.