Complex sentence: He was employed from March 1954 to December 1955 as commercial correspondent by Bahoshy Brothers Co. before he joined well-known Coronet Bookstore in Baghdad, a highly successful family business for 20 years in the 1950s and 1960s before Baathist government's nationalization program of imports.
Split into simpler sentences: He was employed from March 1954 to December 1955 as a commercial correspondent with the Bahoshy Brothers Co. before he joined his family business, the Coronet Bookstore in Baghdad. The store had been a highly successful business in the 1950s and 1960s before Baathist government's nationalization program of imports.