Complex sentence: After Altman completed the film, it was the subject of a lawsuit by film producer Marvin Worth, who had obtained the film rights in two books written by Bruce, and alleged that Altman's movie infringed the copyrights in those books.
Split into simpler sentences: After Altman completed the film, it was the subject of a lawsuit by film producer Marvin Worth. Worth had obtained the film rights in two books written by Bruce, and he alleged that Altman's movie infringed the copyrights in those books.