Combustion mode means type of combustion: homogeneous, stratified,...
The combustion mode is involved in the modeling of the exhaust.
The DRVICE01E enables several combustion mode since an engine can have several combustion strategies for the same working point, with different pollutant emission levels.
What example file are you speaking about?
You don't need to have a BMEP file for each mode when you are in standard mode. 1 file for all mode is ok.
If you are in expert mode, you have to create the map, as explained in the documentation of the submodel.