Flood fill the selection with black. We'll want our button hole to be black later for the rollover effect. Now let's make our right button in exactly the same fashion we used for the left. Now save this selection to the Alpha Channel and name the selection rightButton. Toggle the layer's visibility off and click on Layer 1 to make it active.
Flood fill the selection with black, then deselect.
Activate your Magic Wand tool and set its Tolerance to 25. With Layer 1 still active, hold down the Shift key and click your Magic wand in each of the black button holes and in the black background surrounding your nav bar. All the black areas should nw be selected. Now just the nav bar itself should be selected. Now let's apply the same effect to our buttons.