Complex sentence: During World War II he was in the dangerous position of opposing the Nazis; though he tried to go about his career as usual, and did, to a limited extent, on two occasions he was forced to go into hiding for several months.
Split into simpler sentences: During World War II he was in the dangerous position of opposing the Nazis; though he tried to go about his career as usual, and did, to a limited extent. On two occasions he was forced to go into hiding for several months.