Export as in save the map from the baker? If so, press bake and that will save all active maps to disk. If you want to export a map from the scene, well, maps aren't saved in the scene, they're saved on your hard drive. You can press the little pencil button next to the map to open the file.
I figured it out. I was trying to bake out the normal and AO maps so I could use them later on in substance painter. When I was attempting to open the maps using the pencil nothing was appearing in photoshop even though I had the .psd baked out. The only thing I didn't have was the file path assigned where the maps would…