I haven't opened the example file yet (my AE machine is currently busy with C4D stuff).
A screen would be somewhat in front of the content behind it, so shouldn't it be that way anyway?
If you really want to adjust it, why not move your dirt layer back?
Now, if you're talking about the precomp containing CC Ball Action, that layer's position should be at the center of your main comp, but the CC Ball Action effect might be putting it somewhere else in the layer's z-space if that makes sense.
Like Szalam said, the CC Ball Action is probably not working in the exact same Z space as the native 3D layers and camera. And I'll second his suggestion that the simplest solution seems to be just to move the "screen" layer back a few points in Z space, if you want to cut down on the parallax.
What the others said. Unfortunately CC Ball Action does not respond to 3D cameras in the same manner like native 3D layers. Depending on what you actually try to do you may get by with using effects instead of 3D, e.g. by using a corner pin effect and manually warping the dirt into place. Also try to keep the dirt in a separate comp with its own camera and link it with pick-whip expressions to your other comp, then combine everything in another comp. That way you may be able to work around the issue by playing with the focal length or again applying corrective effects on the pre-comp.
Thank you all for the help. Yeah its the Ball Action effects that is making the dirt "float" in the air. I pre-comped the dirt layer and this thing didn't happen I don't know why but it works.