How can I quickly determine which planes are associated with different failure types in Dips?

Select File > Export > Export Data to Excel to export all output data from the Dips analysis to an Excel spreadsheet.  In the Excel spreadsheet, if you go to the Plane Intersections tab, you will find the Plane ID #s that correspond to the intersections.  The Plane ID #s are the ID numbers of the planes from the original Dips input data grid.  In the Direct Toppling and Wedge Sliding columns you will find a flag which indicates whether a plane was involved in a particular failure mode with another plane.  For example:  

Wedge Sliding P1 = sliding on both planes

Wedge Sliding P2 = sliding on one plane

Direct Toppling C1 = direct toppling

Direct Toppling C2 = direct toppling (oblique)

You can filter the spreadsheet data as necessary, do some manual processing of the results, and then import back into Dips.

Unfortunately, there is no simple way to highlight the individual planes involved in wedge sliding or direct toppling on the stereonet.