Originally Posted by
Korpo
Buildings with multiple floors often stand in for navigating a plane of existence. Planes typically have 7 sub-planes, but our access to individual sub-planes is restricted by how far we have developed that particular body as a vehicle of consciousness. (We actually usually do not perceive sub-planes we cannot access.) Typically the ease of moving between sub-planes is reflected in the means to do so. It's continuum from really hard to really easy - a vertical climb is hardest, then walking up a slope (depending on gradient), walking up stairs, taking an escalator, taking an elevator, flying, instantaneous changes. This is how I typically experience changes between sub-planes.
Anyway, in general I would say the dream represents learning to activate more chakras of that body to actually learn to navigate the respective plane. As somebody who has such a rich dream life, this might very well be the lower mental plane as you shouldn't have such problems on the astral plane. Not much more can be said here than that a particular body or vehicle of consciousness is typically developed through simulations that focus on parts of its abilities - like here the mobility between sub-planes and being able to tell which sub-plane one is on. It's possible that this inner sense was trained in isolation in order to make better use of it in the future.
You might actually benefit from reading Kurt Leland's "The Multidimensional Human" to give yourself some context on what might be going on in such dreams, and some practices you might want to try. :)