Complex sentence: Blume finds his operation of a multimillion dollar company to be unsatisfying and is frustrated that his marriage is failing and the two sons he's putting through Rushmore are boorish and unrepentant brats spoiled by their Mother.
Split into simpler sentences: Blume finds his operation of a multimillion dollar company to be unsatisfying. He is frustrated that his marriage is failing and the two sons he's putting through Rushmore are boorish and unrepentant brats spoiled by their mother.