Ekin Aydemir

I have a 3d render of a product, z pass layer is depth information, black means far away and white means near. I want to add depth of field effect to this image. I've duplicated my render, blurred it and I want to mask it with z depth. But when I mask it to below, nothing happens, blurred image is not masked. z pass layer has levels adjustment for better defining. I've included the file below. z pass.afphoto