You are using Simple Survey and would like to use different field sets for your landing page depending on the Initial Rating.
By default, Simple Survey will use the "Survey Fields" field set for the survey landing page when no other field set is specified. However, you can also create additional field sets and reference them in your survey email template.
Referencing multiple custom field sets can be done by editing the HTML version of the Email Template.
Once you've created your custom field set on the Survey object and have added your desired fields, please follow the steps below:
1. Navigate to Setup--> Communication Templates--> Email Templates
2. Select the Simple Survey Folder, and Select the Survey Template you wish to edit to include multiple field sets.
3. Click the button titled "Edit HTML Version.
4. Scroll down to the section that displays the HTML links for the initial ratings.
5. Within the rating link, you will need to add in your field set parameter.