How I do I display a link back to the parent category

To display a link back to the parent category, please go to Joomla's module manager, create a new module, choose breadcrumbs as type. Assign the module to the gallery pages, and assign the module to the breadcrumbs position in the template. You can see on this page the joomla breadcrumbs module is showing at the top of the page. The breadcrumbs module will make links back to all the parent categories of the current gallery.