Complex sentence: After Carey and Hall played "Dreamlover", Mottola expressed mixed feelings towards the song, then approaching Walter Afanasieff to add some needed instrumentation and flavor to it.
Split into simpler sentences: After Carey and Hall played "Dreamlover", Mottola had mixed feelings towards the song. He approached Walter Afanasieff and asked him involve himself in the project and add some needed instrumentation and flavor to it.