You don’t need to have full split for this movement but I do recommend to put the hoop very low if this is your first attempt to do something on the top bar of the hoop.
Tilt your body back and lift both legs together up (as seen in the video). If you don’t have enough power to tilt back and lift both legs together yet try to first work on that, because if you will try to skip this part you will end up with a bad technique.
To work on this you can try sitting in the hoop and attempt to do pull ups using your hands while bringing your knees closer to your chest at the same time.
I hope you’ll enjoy the video and please don’t hesitate to write me with any question.