Minecraft wiki entry for Map, associated text: In Bedrock Edition the player can place copies of locator maps in item frames in order to create a land mark. The marker is a green dot that resembles the shape of the player's marker, but in green color. The position the marker points at depends on the direction the item frame is facing. It is worth noting that the markers work only on copies of the same map. Other maps of the same area do not show the existing markers that the player(s) had placed.