Hidden dimensions are not returned as refinement options.

A hidden dimension is like a regular dimension in that it is composed of dimension values that enable the user to refine a set of records. It differs from a non-hidden dimension in its accessibility in the user interface.

If a dimension is marked as hidden, the MDEX Engine will not return the dimension or any of its values as a refinement option in the navigation menu. However, if a given record is tagged with a value from a hidden dimension, the MDEX Engine returns this value with a record query, assuming the dimension is configured to render on the product page.

Although hidden dimensions are not rendered in UI navigation, records are still indexed with relevant values from these dimensions. Therefore, a user is able to search for records based on values within hidden dimensions.