[DanCooper]

To be precise (in that order):

1. by folder structure (VIDEO_TS or BDMV)
   
2. by file name or full path (depends on your settings) based on Video Source Regex Mapping (left list in komplex' screenshot)
   
3. by NFO (<videosource> node)
   
4. by Video Source File Extension mapping (right list in komplex' screenshot)