Complex sentence: Soyinka founded another theatrical group (after Nineteen-Sixty Masks), called Guerrilla Unit, its aim being to cooperate with local communities analyzing their actual problems and then responding to some of their grievances in dramatic sketches.
Split into simpler sentences: Soyinka founded another theatrical group (after Nineteen-Sixty Masks), called the Guerrilla Unit. Its aim was to work with with local communities in analyzing their problems and then responding to some of their grievances in dramatic sketches.