I developed this model through study and personal exploration. I first introduced it in my Metaphysics: Theory and Practice class in 1987 to help clarify the multi-dimensional nature of consciousness. The top level of the Superconscious Mind where we are all one and there is no reduction of consciousness, but one can experience it in an exceptional experience called Cosmic Consciousness. I have an article you can find through the menu on the left named Cosmic Consciousness where I describe my experience of it.
The next level down is the Collective Unconsciousness. At this level we are interconnected and also there can be a form of oneness so it is open on the top but is being reduced as it is focused or funneled or simplified for our mind to be able to grasp it while still in a physical body.
Then below that is the Personal Unconscious where we are separate individual beings with individual consciousness. It contains our personal memories including past life memories. Our history, traumas, insights, skills, body memory and what makes us us.
Below that is the very small point of consciousness we call the conscious mind moving along the space time continuum, one moment after another. It necessitates the reduction of mind to this small point in order to live life in a physical body. As long as we are alive we are limited in our ability to experience and describe the higher more expansive levels of mind. This level we experience most of our waking life.
Between each level is a threshold one can feel yourself push through as you go into deeper altered states, normally losing awareness in the physical world when we go deeper and it is difficult to bring to the conscious mind what we experienced in the higher states of consciousness. But the more we develop our consciousness the more we can experience and recall these higher states of consciousness. We often experience these during an exceptional experience, usually a brief glimpse, yet it has a huge impact that can be potentiated into a spiritual awakening or spiritual emergence.