You can change theme’s CityBook Add-Ons plugin -> Listing Type Builder element template from child theme by copy .php files from azp_templates to child-theme/azp_templates/ folder.
For example, you want to change author widget output on single listing page. And the widget use template from plugins/citybook-add-ons/azp_templates/azp_widget_author.php so just copy azp_widget_author.php into azp_templates folder on your child theme then edit.
