Real gravity decreases in strength via the inverse square rule as it always does (i.e. if you double the distance, the gravitational strength drops by a quarter).
IMO artificial gravity uses the same relationship, but it is a pseudo-force like centrifugal force - it doesn't exist outside of the object generating it (a rotating space station may generate 1g within its habitation ring, but it's not pulling in everything around it as if it's an object with a 1g gravitational field).