The Star Rating facet type allows users to filter by average rating.
|Data Source||The custom field containing the average rating|
You must have an existing custom field that stores the average rating. This
average rating field must contain a numeric value between 1 and 5.
If you are using the WooCommerce average rating, set the Star Rating facet’s
Data source to the “Average Rating” field under the “WooCommerce” heading.