Update 29 Mar 2018: These have been identified as staff quarters for Hong Kong Electric - see Ashley's comment below.
The location of the marker is approximate, but photos appear to show the three buildings on the slope above the Shing Kwong Church.
I think they could be connected with the Belilios Reformatory that was nearby, possibly as accommodation or classrooms, but I'm not sure yet.
In pre-war photos they each have a pitched, tiled roof. Post-war photos show buildings with a flat roof, but otherwise they look very similar. I guess they were damaged during the war years, then renovated with flat concrete roofs after the war.
Can you tell us more about them? Please leave a comment below.