Hold the Control key as you click the elements you want to group, then right-click the selection and choose "Group". You can also use the keyboard shortcut Control + Shift + C.
Flow Direction specifies the direction in which the elements are laid out when their corresponding position property (x or y) is set to "auto".
Set Loop to "True" to create a repeating composition. Use it along with Plays to set the number of repetitions.
Right-click the composition and choose "Ungroup".
Double-clicking an element will focus the editor on the composition it is part of.
It is possible to set a composition to loop over time, enabling you to define an animation only once, then repeat it as often as you want. To do this, you need a composition with a fixed duration (a duration of "auto" won't work), then you set Loop to "True". Plays allows you to set how many times it repeats. It will play endlessly when set to "auto".
At the moment, you can't use video or audio clips inside looped compositions. The clip will play only once. A video or audio element has its own Loop setting that can be used for this purpose.
Examples of looping compositions are provided in several demo templates (click New under Templates). An animated background is one of the most common uses.