Related Questions:
Can my Booking be in two pipelines at once?
How do I add my Booking to several different pipelines simultaneously?
How do I add a second Pipeline to my Event?
Answer:
Bookings can only be active in one Pipeline at a time. A workaround would be to use a Custom Field to map where it is at for one of the Pipelines that run simultaneously. You could have a Picklist which has the different stages as options to pick from to help keep track.