I read Dune many years ago and I think I remember reading another book that may have taken place in the same world, but I'm not sure. Why?

The theme of the series is basically how societal power dynamics play out on a multi-millennial timescale. The author called the series Dune after he noticed that, from above, sand dunes form a wave pattern over the land, so suddenly something he had only thought about at a local level had much greater meaning from this higher perspective of time. Anyway I thought it seemed up your alley. The first novel is a classic but it just scrathes the surface thematically.