I first learned about what an Assemblage Point is decades ago while reading the Carlos Castaneda books where Yaqui shaman teachings were included in the storytelling. Basically, everything that can be seen, experienced, and known is an emanation of the Absolute, or Pure Spirit according to Castaneda.
The thing is that our ordinary consciousness limits what we perceive to a restricted band. So,
whatever our continued focused attention is on, that's the band that we’re perceiving as reality or the world view. That restricted band is what Castaneda’s Yaqui tradition called our “assemblage point.”