wp_nav_manu() displays a navigation menu. We can call different menu by assigning a different $menu. But the is no straightforward function to get only a submenu. For example, we may want to display a submenu on the sidebar for easier navigation.
The following code snippet can do just that. Simply add a submenu in arguments for the function wp_nav_menu(), and pass the first-level menu item name that has the submenu we need for display.
Add following code in function.php, or your own custom plugin.
add_filter( 'wp_nav_menu_objects', 'submenu_limit', 10, 2 ); function submenu_limit( $items, $args ) { if ( empty($args->submenu) ) { return $items; } $parent_id = array_pop( wp_filter_object_list( $items, array( 'title' => $args->submenu ), 'and', 'ID' ) ); $children = submenu_get_children_ids( $parent_id, $items ); foreach ( $items as $key => $item ) { if ( ! in_array( $item->ID, $children ) ) { unset($items[$key]); } } return $items; } function submenu_get_children_ids( $id, $items ) { $ids = wp_filter_object_list( $items, array( 'menu_item_parent' => $id ), 'and', 'ID' ); foreach ( $ids as $id ) { $ids = array_merge( $ids, submenu_get_children_ids( $id, $items ) ); } return $ids; }
For instance, I would like to display submenu content from “Dropbox”.
Here is how to make the call:
$args = array( 'menu' => 'Main', 'submenu' => 'Dropbox', ); wp_nav_menu( $args );