Apple Final Cut Pro 7 - Manual (Page 91)

Chapter 4 Working with the Canvas and Timeline 91
Set a video destination track before placing clips in a sequence:
Drag the v1 Source control to the V2 Destination control to specify that the V2 track
1
should be the destination track. Click the Source control to connect it to the V2
Destination control, if necessary.
Connect the v1 Source
control to the V2
Destination control.
Press End to move the playhead to the end of the sequence. Drag a clip from the 2
Viewer to the Overwrite section of the Canvas Edit Overlay.
The clip’s video item is placed in the video track you selected.