If you have Campaign progress: 1 level or other,and you want to reset,you click on the ''Edit profile'' button then Eric Gurt will ad a ''Reset campaign progress''.
I honestly don't really understand why does this need to be implemented. I don't actually know a single person who would want to do this. I don't think people would want to reset their campaign progress since they can just brag about finishing the game in their Profiles.