Or nothing is hidden from Him because He can see anything and everything that He chooses to see at any given moment in time. He is not limited in any way.
This does not require Him to be present everywhere simultaneously.
The whole heart of this debate is always missed by Calvinists and others who cling to these unBiblical ideas. The discussion isn't what God CAN or CAN'T do, but what DOES God do? If we examine the Scriptures we see the truth.
Again, there are tons of contradictions that you cannot deal with if you cling to omnipresences. There are no contradictions if you remove your theological predispositions and study God's Word anew!
Please allow me introduce you to God as He really is: God is wherever He wants to be, whenever He wants to be there. God is not some metaphysical force that has no choice where He goes and what He does. He is living, and He is real. If there is somewhere that He chooses not to be, then He doesn’t have to be there!