<?php $nb_sidebar = nimbus_meta_data('radio_widget_sidebar') ? nimbus_meta_data('radio_widget_sidebar') : 'sidebar';
    if ( is_active_sidebar( $nb_sidebar )  ) : ?>
    <aside id="sidebar" class="nb-col-md-4 sidebar widget-area" role="complementary">
        <div class="nb-sidebar-content">
            <?php dynamic_sidebar( $nb_sidebar ); ?>
        </div>
    </aside><!-- .sidebar .widget-area -->
<?php endif; ?>