In your user settings you can define how many note's levels you would like to see.
Note depth
defines for how many levels you want to see the title of notes. You should normally put that to a large number like 66 because you want to see all notes.
Note text threshold
defines up to which level you want to see the note's text. This should normally be a smaller number (like 6) so that you don't have to scroll too much if two people got into a length 'discussion'.