Using the Hierarchical filter (Hfilter) functionality, you can present the data in a Hierarchical, expandable view as a data tree, drop down or list. Some good examples of data that can be used in a Hierarchical filter are category/brand information, or geographical data such as continents/countries/cities. 

To start using Hierarchical filters in your project, enable it using the checkbox option in Project settings section. Once you have set the Hierarchical filter in the Admin part of the project you can start using it in StoryTeller.