The Oxford dict. interprets reciprocate as "experience the same (love, liking, or affection) for someone as that person does for oneself". For example, "her passion for him was not reciprocated."
I don't quite understand "for oneself" in this interpretation. It's easy for me to fall into the illusion that "the person (love, like) himself/herself."
So, what does "for oneself" mean here?