Copy and paste the following code into your child theme’s functions.php file:
function my_graphene_slider_post_type( $post_types ) {
return array( 'post', 'custom-post-type' );
}
add_filter( 'graphene_slider_post_type', 'my_graphene_slider_post_type' );
Replace custom-post-type with your own custom post type. In the above example, the standard “post” post type will also be displayed in the slider. If you don’t want that, just remove the “post” post type so the code looks like this:
return array( 'custom-post-type' );