For my work experience - I have dual job roles of both HR and Personal Assistant (as one job), but just choosing 1121 for my NOC - as the HR is a larger element of the two.
You are free to choose which NOC you will go with, just make sure that it is NOC 0, A, or B job and the majority of the job responsibilities and duties of that NOC are covered in your experience letter. Good Luck!
