Do one of the following:
Choose Window > Video Timeline (or press Command-7).
Click the Show/Hide Timeline button in the lower-right corner of the Motion project window.

Note: To collapse the entire Timing pane (Timeline, Audio Timeline, and Keyframe Editor), make sure that all three buttons in the lower-right corner of the Motion project window are dimmed.
Do one of the following:
Drag the toolbar up or down.
Drag the boundary (the gray line) between the File Browser, Library, or Inspector and the Timing pane to the left or right.
Deselect the āiā button in the lower-left corner of the Motion Project window to widen the Timing pane (and hide the File Browser, Library, and Inspector).