MVC which controller to use on a nested route

I have a simple question regarding the MVC pattern.

Imagine this route: courses/:course_id/lessons/ to fetch all the lessonsof a course.

Which controller would be better to use in the order to serve this request?
CoursesController or LessonsController ?

Honestly i can't see "pros and cons".

Of course someone with much more experience then me could explain to me the best way to use in the order to resolve this kind of requests.