Complex sentence: Miller was concerned about the publication of "Sexus" in the US, as he felt it possible his ex-wife Beatrice, the model for Maude, would bring a lawsuit for her portrayal in the novel.
Split into simpler sentences: Miller was concerned about the publication of "Sexus" in the US. He felt that it was possible that his ex-wife Beatrice, the model for Maude, would bring a lawsuit for her portrayal in the novel.