Affecting objects on other Layers?

I needed to create some different layers to be able to have some objects be in front or back of other objects without having to use all active objects to be able to have them in front of my caracters who are actives.

I have a crosshair and a condition that when it is over an enemy and i press left button it shoots him and so on.. the problem is that this condition dont seem to work now when the crosshair and the enemy is on different layers?? Is there any way around this?