Filter tag cloud

add_filter( 'widget_tag_cloud_args', 'filter_tag_cloud_widget', 10, 2 );

function filter_tag_cloud_widget( $args, $instance ) {
    /** Check if Taxonomy is Tags and Element ID or Extra class name settings is footer */
    if ( isset( $args['taxonomy'] ) && 'post_tag' === $args['taxonomy'] && ( 'footer' === $instance['el_id'] || 'footer' === $instance['el_class'] ) ) {
        $tag_id          = array( 258, 301, 4224 ); /* Tag ID */
        $args['include'] = $tag_id;
    }

    return $args;
}