How to add filter option above the ox_options[‘baseTpl’] of fancybox

$fancybox_options['baseTpl'] = '<div class="modula-fancybox-container modula-lightbox-' . $settings['gallery_id'] . '" role="dialog" tabindex="-1">' .
                                       '<div class="modula-fancybox-bg"></div>' .
                                       '<div class="modula-fancybox-inner">' .
                                       '<div class="modula-fancybox-infobar"><span data-fancybox-index></span>&nbsp;/&nbsp;<span data-fancybox-count></span></div>' .
                                       '<div class="modula-fancybox-toolbar">{{buttons}}</div>' .
                                       
                                       '<div class="modula-fancybox-navigation">{{arrows}}</div>' .
                                       '<div class="modula-fancybox-stage"></div>' .
                                       '<div class="modula-fancybox-caption"><div class="modula-fancybox-caption__body"></div></div>' .
                                       "</div>" .
                                       "</div>";

I would like to add filter option on the lightbox gallery.