Finally i cant get subcategories from a custom post type category and everything works fine. The problem is when i want get the same but with a dropdown for responsive. Is possible? i need hide empty terms too. thanks!
here the code:
<ul>
<?php $tax = get_term_by('slug', 'cursos', 'portfolio_category');
$tax_id = $tax->term_id;
$args = array(
'child_of' => $tax_id,
'taxonomy' => 'portfolio_category',
'orderby' => 'name',
'show_count' => 0,
'pad_counts' => 0,
'hierarchical' => 0,
'title_li' => '',
'hide_title_if_empty' => 0
);
wp_list_categories($args); ?></ul>