Hide one section of a questionnaire from employee

Summary

We need to hide parts of a questionnaire from the employees once shared

Content

Hello,

We need to hide parts of a questionnaire from the employee once the review is shared with the employee. Only manager should be able to answer these questions and only manager should be able to see the answers. I believe this can be achieved by customization through expression language.. general theme for this should be something like "for this particular performance document template type, hide when role = worker or task code = acknowledge performance review".. 
I am not sure exactly how to achieve this, any help/documentation would be greatly appreciated!