Customizr show subcategories in parent category

<?php do_action( '__before_main_wrapper' ); ##hook of the header with get_header ?>
<div id="main-wrapper" class="<?php echo tc__f( 'tc_main_wrapper_classes' , 'container' ) ?>">

    <?php do_action( '__before_main_container' ); ##hook of the featured page (priority 10) and breadcrumb (priority 20)...and whatever you need! ?>

    <div class="container" role="main">
        <div class="<?php echo tc__f( 'tc_column_content_wrapper_classes' , 'row column-content-wrapper' ) ?>">

            <?php do_action( '__before_article_container'); ##hook of left sidebar?>

                <div id="content" class="<?php echo tc__f( '__screen_layout' , tc__f ( '__ID' ) , 'class' ) ?> article-container">

                <?php
                    get_header();
                    // get current category
                    $current_cat = get_category(get_query_var('cat'), false);
                    // set args for wp_list_categories
                    $args = array(
                        'child_of' => $current_cat->term_id,
                        'hide_empty' => 0,
                        'hierarchical' => true,
                        'depth'  => 1,
                        'title_li' => '',
                    );
                    wp_list_categories($args);
                ?>

                </div><!--.article-container -->

           <?php do_action( '__after_article_container'); ##hook of left sidebar ?>

        </div><!--.row -->
    </div><!-- .container role: main -->

    <?php do_action( '__after_main_container' ); ?>

</div><!--#main-wrapper"-->

<?php do_action( '__after_main_wrapper' );##hook of the footer with get_get_footer ?>