To open the Segue Editor double click on any audio item on the log, or right-click on an item and choose the Adjust Segue of Select Item option
When this window opens you will see 3 waveforms as follows:
- Waveform of the previous track
- Waveform of the current tack (the one you selected)
- Waveform of the next track
From this window you can drag these waveforms left and right to adjust their respective extro points, the purple line on the waveform shows you the volume of that track.
There is also a checkbox titled with the option of Fade, selecting this on an item will make it's audio fade out when the extro point is reached (based off your Fade threshold and duration settings)
You can use the zoom control in the bottom left to zoom in or out of the waveforms to see them in more or less detail.