Two flyers swing side-by-side (each has half of the bar). Many tricks are possible - Splits, Planche etc. Only one of the pair makes the catch. The second flyer needs to then get out of the position and turn around to be ready when the first flyer comes back to the bar for the return. They can then remount together.
You can find out more about this trick in my books:
Thanks to Susan, Phil, Alex and Max for providing videos for this page.