The contemplative traditions each have some way of talking about a “higher self” – an egoless ego, the selfless self, our Buddha nature, Atman, the Divine Indwelling. The primary characteristic of this higher self is that it operates with a lack of concern for chasing self-interested desires. It is at peace and no longer seeks satisfaction from the world. It lives purely to do the will of God, simply to serve the Good.
These ideas of a higher self sometimes become confusing because they are discussed in terms of ontology. Because each tradition has very different models of the self, they will likewise have different models of what constitutes a “higher self.”
Perhaps an easier way of thinking about these concepts is in terms of the Higher Self as a Mode of Being. The Higher Self spoken of in various ways by various traditions is simply a human being who has achieved and operates with Purity of Heart. However one conceptualizes it, it is a way of being in the world.
Contemplative practice is a, perhaps the, way through which one allows themselves to be transformed into that kind of person.