Add Custom Navigation Menu to Footer

First, you’ll need to register the new menu with WordPress. To do this, add the following code to your custom_functions.php file:

register_nav_menu('footer','Footer Menu');

function custom_footer_menu() {
  wp_nav_menu(array(
    'container' => '',
    'menu_id' => 'footer_nav',
    'fallback_cb' => 'thesis_nav_menu',
    'theme_location' => 'footer',
  ));
}
add_action('thesis_hook_footer','custom_footer_menu');  

Once this is done, you’ll go to Appearance > Menus, and build your new footer navigation menu.
First, click the + tab, assign a menu name (such as Footer Menu), then click the Create Menu button.
Then, add your desired items to the menu you just created – remember to click the Save Menu button when you’ve finished your selections!
Now, when you view your site, you’ll see your newly created footer menu in place at the bottom of the page!