This filter is applied within the breadcrumb_navxt class in the find_posttypes() function. It provides a method to override the default hierarchy display choice for custom post types. This filter was introduced in version 6.0. It receives three parameters:
- $default_hierarchy_display – (boolean)(required) The default choice to either display or not display a hierarchy for the custom post type
- $post_type – (string)(optional) The name of the post type that the default hierarchy type applies to
- $hierarchy_type – (string)(optional) The hierarchy type (BCN_DATE, BCN_POST_PARENT, or a valid taxonomy name) that Breadcrumb NavXT is going to use as the default for the custom post type