Yes. God understands Himself through Himself because, although in us sense or intellect is distinct from the sensible or intelligible object (since both are in potentiality), God has nothing in Him of potentiality (since He is pure act, i.e., His intellect and its object are altogether the same) so that He neither is without the intelligible species (as is the case with our intellect when it understands potentially) nor does the intelligible species differ from the substance of the divine intellect (as it differs in our intellect when it understands actually) but the intelligible species itself is the divine intellect itself: and thus God understands Himself through Himself.
As for us, the reason why we actually feel or know a thing is because our intellect or sense is actually informed by the sensible or intelligible species. And because of this only, it follows that our sense or intellect is distinct from the sensible or intelligible object, since both are in potentiality. God, however, is a pure act.
Note RO3: Existence in nature does not belong to primary matter, which is a potentiality, unless it is reduced to act by a form. Now our passive intellect has the same relation to intelligible objects as primary matter has to natural things; for it is in potentiality as regards intelligible objects, just as primary matter is to natural things.
Hence our passive intellect can be exercised concerning intelligible objects only so far as it is perfected by the intelligible species of something; and in that way it understands itself by an intelligible species, as it understands other things: for it is manifest that by knowing the intelligible object it understands also its own act of understanding, and by this act knows the intellectual faculty.
But God is a pure act in the order of existence, as also in the order of intelligible objects; therefore He understands Himself through Himself.