sub-submenu walker method - wordpress

Question

i have a walker class applied for my submenu but how do i get the sub-submenu item into this code?
below is my code
functions.php
<?php
class wp_submenu_class extends Walker_nav_menu {
function start_lvl(&$output, $depth) {
$indent = str_repeat("\t", $depth);
$output .= "\n$indent<ul class=\"submenu\">\n";
}
}
?>
header.php
<div class="navi">
<?php wp_nav_menu( array(
'menuitems' => 'mymenu',
'container' => '',
'container_id' => '',
'menu_class' => 'topmenu',
'menu_id' => '',
'items_wrap' => '<ul id="" class="%2$s">%3$s</ul>',
'walker' => new wp_submenu_class() ));
?>
</div>

Answer 1

you haven't specified an end_lvl for your class.
<?php wp_nav_menu( array(
'menu' => 'Menu 1', // REPLACE NAME WITH YOUR MENU
'container_class' => 'menu-header',
'menu_class' => 'nav-menu',
'depth'=> 3, // CHANGE THE VALUE WHICH LAVEL YOU CAN DISPLAY.
'menuitems' => 'mymenu',
'container' => '',
'container_id' => '',
'menu_class' => 'menu-header', // MENU CLASS
'menu_id' => '',
'items_wrap' => '<ul id="" class="%2$s">%3$s</ul>',
'walker' => new wp_submenu_class() //function
));
?>
class wp_submenu_class extends Walker_Nav_Menu {
function start_lvl(&$output, $depth) {
$indent = str_repeat("\t", $depth);
$output .= "\n$indent<ul class=\"submenu\">\n";
}
function end_lvl(&$output, $depth) {
$indent = str_repeat("\t", $depth);
$output .= "$indent</ul>\n";
}
}