Walmart has a hair salon in many of their stores. Walmart's primary business model is not hair but product sales. But obviously Walmart wants you to get their hair cut at their salon. This is similar to the government stepping in and saying that the store must allow other Salon's equal placement in their building. They own the building.
It would be anti-competitive to do something to prevent other salons from opening down the street or lowering the prices in their salon to bellow cost to push out competition. But I don't buy that they can't do what they want in their own store.