For the purposes of chess the domain knowledge is the game rules. And from this pov there is really not much to describe, knowing en-passant exists is the peak of domain knowledge.

The other things you describe, such as endgame tables, are really more related to the domain of chess-computing, a subdomain of algorithms, and likely something you exceed your friend's knowledge in.

Getting to a high rank in chess isn't about better domain knowledge, is about application and experience.