Hierarchicle Custom Post Type | ( get_the_term_list() ? hierarchical )

CUSTOM POST TYPE:

• product

TAXONOMY:

• product-category
• brands

The question is, How can I have a sidebar where the parent is the BRAND and under this parent the CATEGORIES in HIERARCHICAL mode (the categories & subcategories should be related to “the parent“).

For now I`m using this code:

$output = '<ul>';

$brands = get_terms('brands');
$count = count($brands);
if ( $count > 0 ):

	foreach($brands as $brand):

		$output .= '<li>'.$brand->name.'</li>' ;

		$args = array('post_type' => 'product', 'brands'=>$brand->slug ,'post_status' => 'publish', 'posts_per_page'=>'1000', 'orderby' => 'name');
		$products = get_posts( $args );

		foreach( $products as $post ) : setup_postdata($post);

			$p_categories = get_the_term_list($post->ID, 'product-category','<li>', '</li><li>', '</li>');

		endforeach;
		wp_reset_postdata();

		$output .= '<ul>'.$p_categories.'</ul>';

	endforeach;

endif;

$output .= '</ul>';

echo $output;

This code works, but the categories are not hierarchicle. Any IDEEA ?