OK - so there are of course more "grounds" that can be alive in immediate awareness..
There is the Ground of seeing and seen, absent of I anywhere.
There is the fertile darkness, ground of form.
There is bliss, a ground of experience uncovered when resistance to experience falls away.
There is love, another ground of experience uncovered in a stable way when the sense of I falls away.
And there is wisdom, yet another ground of experience uncovered in a stable way when the sense of I falls away.
The Ground of seeing and seen is that which is always here, the awake emptiness everything arises within, to and as. When there is identification with an aspect of form, this Ground tends to go into the background and not be noticed much. But at some point, it awakens to its own nature as the Ground of seeing and seen, and the field of seeing and seen, absent of I anywhere. When Ground awakens to itself while still functionally connected with a human self, it seems that the awakening it centered in the head.
The fertile darkness seems to be the ground of form. This awakening seems to be centered in the belly.
Bliss is a stream of quiet joy, in the midst of any experience. It surfaces when resistance to experience falls away, it is noticed in the absence of the drama of fighting the content of experience. In my experience, this one seems to be an aspect of the heart awakening.
Love and compassion is Spirit relating to itself as second person, in the form of another being. When Spirit recognizes all form as itself, and also allows for a transparent overlay of I and other, there is love and compassion. This is an heart awakening.
Wisdom is the immediate recognition of the Ground of seeing and seen, inherently absent of I anywhere. It is Spirit recognizing itself as the field of seeing and seen, absent of I. It is also Spirit arising as form, functionally connected with a particular human self, and able to function effectively in the world of form as and through this human self.