Can you explain what you mean? The OSM data base (which you can download), doesn't have "layers". It's all just one big topologically connected pile of objects.

Can you explain what you mean? The OSM data base (which you can download), doesn't have "layers". It's all just one big topologically connected pile of objects. You are free to make a local map with OSM data, and then, in your browser, or GIS software of choice, overlay anything else you want on it.