Good ol' selling from the right hand to the left hand?
More than two arms. There is a multibillion dollar company where I live that is an Octopus on steroids. They own an auto dealership to sell themselves fleet vehicles. They own a refinery to sell gas to fuel their operations. They own a property management company to look after their real estate transactions. They own a rail line to deliver their products to market. They own an insurance company to insure their operations and fleet vehicles. The government gives them grants to expand because they say that they will hire more workers. May be true but they put the competition out of business. They own their own private police force for security. They own a house building company to build homes with their products. They own a chain of hardware and building supply stores to sell their products.
It is quite a system. Write offs and profits in a convoluted business world.