Complex sentence: While working for Lifemark, Scrushy moved to St. Louis, Missouri, where he worked the the regional director of the respiratory therapy division and then to Houston where he became the company's chief operating officer.
Split into simpler sentences: While working for Lifemark, Scrushy moved to St. Louis, Missouri, where he worked as the regional director of the respiratory therapy division. He then moved to Houston where he became the company's chief operating officer.