Given this information from his biography I searched for Leroy Kuhn and found that he had a membership in the Military Surgeon Association:
Yet another Google search yielded this gem from the History of Medicine and Surgery and Physicians and Surgeons of Chicago, 1922.
Army Medical Command (AMEDD). I had asked why I could find nothing on the term "Surgical Group." They explained that the peacetime Army medical structure (which was used upon our initial entry into WWI) was heavy on hospitals did not have the capability to push forward to be closer to the front. Thus the birth of Surgical Groups or Teams. The reason I couldn't find any information on Surgical Group No. 7 is that these groups typically were called "Teams."
However, numerous searches for Surgical Team No. 7 have yielded nothing. Presumably, Surgical Team No. 7 would have been attached to Hospital No. 7. I have found information on this hospital, but nothing about Dr. Kuhn. So it appears it is time to order his military service record. Records prior to 1950 are archival and are open to the public for a copying fee. They can be ordered here at the National Archives eServices website.