Under Parent is updated with your selection.
Trajectory lists all of the trajectories under the
specified parent. By default, New is selected. This moves a
mirrored trajectory from its original parent to the specified parent. If you select any
other trajectory in the list, the mirrored trajectory is appended in that trajectory.
When Copy is selected, you also have the option to
select and define a Name-Prefix that prepends the trajectory
name.