WEB Booking: book series of app types | booking of part 1 & part 2 (ROF)

Be prompted to book part 2 after part 1 during booking online. In another software, booker.com, we had a feature called series booking. To accommodate booking of patch test and 1st treatment, much like an exam and case history (Part 1), then ROF (Part 2). Clients could then book the online 1st part and be prompted to secure the second part straight after.