Create three layers:
1) the first will be the bg;
2) the second will have 2 sprites for masks;
3) the third the player-sprite.
On the layer mask, set FORCE OWN TEXTURE to YES. This layer should have two objects: one tilebrackground (black) and a circular-mask-sprite (or other color you want). Remember, the circular sprite should have a color other than black. The white circle sprite should blend mode DESTINATION OUT effect .
Set PIN behavior to circular-mask-sprite connect to player-sprite in Event Sheet.