The first level, Anva Upaya, which includes pranayama, meditation, mantra chanting, exercises, and yoga.
The second level, Shakta Upaya. This is much more subtle; it is the stillness that you experience at the end of doing all these exercises; it is more internal.
There is very little that you do, in fact everything is happening. There is no doer there, nobody doing anything, yet, it is happening; you feel that Shakta Upaya, it is very subtle.
The third level, Shambava Upaya is a step beyond the Shakta Upaya; just recognition, just awareness. It suddenly dawns; you have no clue, you have no say in it, you can’t do anything about it.
You are walking, watching a sun set, suddenly, something happens, something opens up. You meet someone; suddenly, you feel some sense of elevation, joy.
Whether you are meditating, sleeping, or doing any work, suddenly an awareness, a wakefulness dawns in you. That is Shambhava Upaya; that happens with grace, blessings or love or something.
The first stage, Anva Upaya, is inevitable. The second stage, Shakta Upaya, is an obvious movement. The third stage, Shambhava Upaya, is a gift.
