EXS 24 Logic Sampler Users Group

I am working on some instrument (sampling my wife's boxes) and going 
deeper in Instrument Editor, and I don't understand the use of the 
option "Groupe" of "Select by" parameter (no problem fot the other 
options) ? Some examples of it ?

Thanks

Powerbook G4 1GHz, 728 Meg RAM, Mac OS 10.3.8, Logic 6.4.3 and 7.0.1
--
G.Ryckeboer