Same Noc Different Designation


I have created profile in canada express entry pool. Having four years work experience from July 2016 to till date as a Assistant. My designation from July 2016 December 2017 was different as an assistant and on January 2017 onwards, I was promoted as Retail Sales Supervisor. Till January 2017 to till date, I have been working as Retail Sales Supervisor. In both designation my company is same.

I am having same job duties of NOC 6211 in both the NOC in a same company. Should I take job description on different letterhead for different desgination or it is acceptable in one reference letter? Kindly assist.