Final Cut Pro – Displaying Source or Auxiliary Timecode
Here’s a fast way to switch your display between timecode tracks.
Each QuickTime clip can have up to three timecode tracks; called Source, Aux 1, and Aux 2.
However, by default, only the source timecode is displayed. You can change this with a mouse click. Here’s how:
Control-click the numbers inside the timecode box in the top right corner of either the Viewer or Canvas. At the bottom of the pop-up menu you will be able to select between all the timecode tracks available in that clip.
Courtesy of Larry Jordan