This filter is applied within the bcn_breadcrumb class in the set_url member function before passing into esc_url() and then setting the internal $url property. This filter was introduced in 4.3. In 4.4 two additional parameters were made available. It receives three parameters:
- $url – (string)(required) The URL that is being set for the breadcrumb
- $type – (array)(optional) The array of type strings for the breadcrumb
- $id – (int|NULL)(optional) The ID of the resource represented by the breadcrumb, will be NULL if no suitable ID exists