It is very much like inception, levels insde levels. You quiet a level as you start your meditaton, and the meditative process keeps putting you into deeper states alpha, beta etc. and all access is “granted” by your ability to calm the storm of the mind, to have clear waters, mud free, so you can see the bottom and dive in, then you realize the bottom is just the muddy waters of the storm even deeper.
I love the kabbalistic description of Briah, where you’d get if you achieve the perfect flow, where it’s all clear, calm, a place where you still have some separation but you stop affirming it. :D