Yes, that is possible, but only to a limited extent. We actually always have the tub at the bottom and the sport seat at the top facing backwards. The upper tub is only possible if the lower sports seat is rear-facing, which means that the child in the sports seat has the tub in front of its face, which is not very exciting. Tub down and sport seat up forward facing also works, but if the big one drops something, it lands on the baby in the tub, not very great either.