What is the right thing to do?

You are approaching an intersection with a yield (give way) sign that includes a priority road diagram showing that your road ends and you must yield to traffic from the right and left.

In this situation, you must give way to the motorcycle on the left and to the blue car on the right. Both vehicles have priority because of the right-before-left rule, which applies when no traffic lights are present.

You cannot drive out before the blue car because it approaches from your right and has priority.

The rule you are seeing here is the basic right-before-left rule at intersections without traffic lights or signs giving priority, except that your yield sign confirms you must yield to all vehicles from both directions before entering.

Therefore, your correct response to yield to both the motorcycle and the blue car is fully correct and follows German traffic regulations.