Reverse Match Frame allows you to search the Sequence for a specific frame of source material on whatever Timeline tracks have their Track Selectors enabled. Remember, it is only searching for one frame, not an entire shot, and it pays attention to which tracks are enabled.
This function has recently been improved. In the past, it searched the audio tracks and only track V1. It will now search all video tracks, if they are enabled.
Reverse Match Frame can be found in Tools menu | Command Palette | Other tab. You would map it either under the Source Window or onto the keyboard (for use when the Source Window is active). See Mapping buttons and menu selections recipe in Chapter 2, Customizing Your Work Environment for more information if you are unfamiliar with mapping.