Complex sentence: Felsenstein was born in Vienna and began his career at the Burgtheater in his birthcity and from 1923 to 1932 was a theater actor in Lübeck, Mannheim, and Bytom, where he first worked as a director.
Split into simpler sentences: Felsenstein was born in Vienna and began his career at the Burgtheater there. From 1923 to 1932, he was a theater actor in Lübeck, Mannheim, and Bytom, where he first worked as a director.