What, like a second map or something? Like a layer "above" the map? You could do subspace like this: Explaining it as the map being the same size but the distances all being much much shorter (so by dipping into subspace, you don't have to go as far).
Could be fun to chart this space or even explore it.
Maybe it has clusters of mass in similar positions to our own stars that operate under different rules: Like worlds without stars -- light as we know it bleeding into this space with the sky always lit white and the 'stars' pinpricks of black.