Complex sentence: Quincy Jones composed the soundtrack for the film, including Soul Bossa Nova, used in a scene at a nightclub, which would later be used as the main theme to the Austin Powers film series.
Split into simpler sentences: Quincy Jones composed the soundtrack for the film, including "Soul Bossa Nova", which was used in a scene at a nightclub. That would later be used as the main theme to the Austin Powers film series.