This picture shows the structure of the low-g facility.
settlement structure

Here is an example of LEO structures with artificial gravity by rotation. In the center is a microgravity docking facility.  

There are 3 boosters on each end where the artificial gravity will be approximately that of Mars (38% that of Earth).  There are 6 boosters along the “spine” that have a lower gravity anywhere that a floor is placed.

There are about 5000-6000 square feet of area with a martian gravity, and the same at gravities less than that.  This assumes areas of 80 x 100 feet available inside the hydrogen tanks of the main boosters.