What you are saying regarding the absence of separation is true, and yet the understanding of “no self” is not really focused on that, so an idea of a greater Self is a greater error than just that of thinking that there is an intrinsic self that we are. If you are interested, there are two sequences of dialogs in Tranquillity’s Secret on aspects of this issue:
This Visceral Feeling of Self (Sequence)
Wisdom traditions say that our belief in our independent selfhood is ignorance. True enough. But they are focused on the belief, and skip over the visceral feeling, which, since it arises viscerally rather than intellectually, must be due to some condition or cause other than inherent ignorance or stupidity on our part.
as a lead-in to: