As a default behavior, whichever biped part is selected in the viewport has its curves displayed in the Curve view. You can also use the Select panel to select biped parts by name. The Select panel works like the Selection Floater; you can invert the selection set or enter a name into the Selection field to find a track.
You can also use the controller window as a selection mechanism. With the Controllers list visible you can click track entries there to work on the curves.
The Workbench toolbar lets you choose the type of curve to display and the coordinate space in which it is displayed. For example, if you know you are dealing with rotational errors, choose a Rot or Quat type curve. If it is an error of positional data, choose Pos.
If you open the Track View – Curve Editor or expand the track bar while you have the Workbench open, you will see a simultaneous display. The views are all synchronized, so selecting a track in one graph editor selects it in all.
When using footstep animation, you can see the footstep keys by opening a Track View – Dope Sheet window.