The hierarchy dropdown facet type
The hierarchy dropdown facet type allows your users to narrow down your listings by navigating the levels of an hierarchical taxonomy using a dropdown field instead of a simple list. This facet type can only be used with taxonomies like categories, locations, etc.
Check this facet in action on our live demo: https://demo.posterno.com/listing-type/place/
This type of facet, supports an unlimited number of indentation levels. In the example below, after selecting a parent category, the "subcategory" dropdown would automatically populate itself with the child categories.
Sort by: the sorting order of the choices by count, or term order.