The Basic Levels of Consciousness
This is what we generally know as our "conscious mind". Though that is a rather misleading name, because it assumes that the other parts or levels of our consciousness are somehow not conscious, and that is simply not true.
This is why I prefer to call this consciousness, the "Me-Self". Some might also know it as the Ego, the Internal Dialogue, the Driver or the Mental Body. No matter how you recognize this level of consciousness, it is the one we can least deny, because to deny it, would be to deny the "I".
The Me-Self is the organizer of thoughts, the analyzer, the main personality and the part of ourselves that continually strives to be more. This is the part of us that "wants" and "learns" directly.
Most known the Other-Self as the Subconscious, which is an okay name, but to me, sub-conscious makes it sound like this level of consciousness is less important or less aware, when it is not. The Me-Self is more in control of the physical body and direct thinking, but not completely. The Other-Self also has control, though generally only over the things that the Me-Self doesn't want to directly regulate, such as breathing or organ functions. Because of this, the Other-Self often uses what we would know as unconscious processes to attempt to communicate with the Me-Self or other beings.
Because the Other-Self has control mostly over the functions physical and energetic body, it's main priority is to cover our physical and energetic needs. If we get physically sick, it signals to the Higher-Self that a remedy must be found. In short, the Other-Self takes care of our direct needs (food, water, shelter, psychological, etc..)
The Other-Self is also the part of ourselves that becomes the Dream Body when we sleep, which is also known as our Energetic Body. The same body that houses our chakras and creation energy. This energetic body is where most of our personal data and gathered information is stored, which is necessary, because although our Me-Self learns directly, it doesn't have enough space to store all that is learned, and in order to learn more later, it must be able to access what is has already learned.
The Higher Self
The Higher-Self is most commonly called the Unconscious. Again, this is misleading, because the Unconscious is not unconscious. It is very conscious, and very aware. So we will call it the Higher-Self.
It is the part of us that draws information, quantum energy and experiences from the collective consciousness and relays it to the Other-Self to be used by itself and the Me-Self. It is also the Higher-Self's job to provide experiences and manifest resources in an attempt to give the Me-Self what it wants, and the Other-Self what it needs.
The Higher-Self is impartial, giving priority to necessity over desire. If necessity is reasonably accommodated, then the Higher-Self will give priority to needs or desires that both the Me-Self and the Other-Self seek in tandem, which is known as Conscious-Coordination. If there is no coordination between the first two levels of consciousness, then the Higher-Self will give priority to one with the most focused will or intent.
Because the Higher-Self is impartial, detached and objective, it is often thought of the part of ourselves that wants the ultimate good for us.
The Collective Consciousness
This would be the source. Or some might think of it as their deity or deities. It is the divine energy. The cradle of everything where creation and destruction exist in their purest forms. This is the level of consciousness that connects all beings on the most basic and the most complex way.
Often, our Higher-Self will connect us to the Collective Consciousness when we need information or inspiration our Other-Self doesn't yet have, or can't find/access another way. It can do this, because all life experiences are essentially sent to the collective consciousness in the end. It is this way, because energy on it's own does not really exist without a separate "outer" self to acknowledge that it does exist, and to bring it into other forms of existence to experience.