Is there free shutlle bus leaving from Terminal 1 to T2 and then T3 at Beijing capital airport?

Cross Terminal Free Shuttle Bus
Every seven minutes, there is a free shuttle bus leaving from Terminal 3 for Terminal 2 and then Terminal 1, (vice versa).

It means the free shuttle bus does leave from Terminal 1 to Terminal 2 and then Terminal 3. Right ? as a return route.

Thank you very much ! it's very important to make sure this for me.