Consists of b¹-g¹-b¹, and c²-a¹-c² (Note the unexplained discrepancies in pitch (b vs c and c vs [near] c♯) between instruction and execution in the video [➺ below]). NB: Example(s) to be replaced with staff-notation.
Sources
Web
College of Piping tutor (Strikes on B & C and first part of 'The Piper of Drummond' [video])