Specifically, the old Schaefer's occupied the space on the southwest corner of 13th and F, which would be the northeast corner of today's Community Center building. Interestingly, a little further to the west, an historic Fire Station is also incorporated into the building. The fire station pre-dates Schaefer's by a couple decades, and my guess is that the commercial building on the corner was built to reflect the design of it's neighbor down the block to the west.
There's a nice little Lincoln Police Department substation in the southeast corning of the Community Center, which gets a lot of use. That's why you'll often see police patrol cars in the curb cut on 13th Street.