What is the right course of action?

You answered correctly. In this traffic situation, you must allow both the cyclist going straight and the motorcyclist approaching from the opposite direction to pass before you turn left. According to German right-of-way rules, when turning left, you have to yield to oncoming traffic (such as a motorcyclist going straight or turning right) and to cyclists or other straight-ahead road users. You may only turn once the intersection is clear. This ensures everyone's safety and prevents accidents. Always remember to check for and yield to oncoming vehicles and cyclists when turning left.