After you make a booking on hold, you can continue shopping the same marketing carrier for the same passenger via a button ''Book Again''. When you click on the button, the passenger details will be copied and you will be redirected to the new search.
Then select the flight operated by the same airline and continue to ''Start Booking''. Passenger details from the previous reservation (1 PAX or more) will be automatically pre-filled and you don't need to put them again.
Watch the full video on this link: https://monosnap.com/file/p96UXAV2gdbiQgUweEBCsbQXe4yxuZ