When building logic in your GetFeedback survey, you’ll choose to base the logic on a response, merge field, or other response attribute. With logic branching based on merge fields, you can create a rule based on any merge field used in your survey.
To make merge fields available for survey logic:
Once you've submitted the survey once, your merge fields should appear within the GetFeedback response table. You can now use the merge fields in your survey logic. Learn more about using survey logic