最初のサブメニュー項目に異なる名前のadd_menu_page（）

サブメニューページの「スラッグ」をトップレベルページの「スラッグ」と等しくすることができ、それらは同じ場所を指します:

 add_action('admin_menu', 'my_menu_pages');
function my_menu_pages(){
    add_menu_page('My Page Title', 'My Menu Title', 'manage_options', 'my-menu', 'my_menu_output' );
    add_submenu_page('my-menu', 'Submenu Page Title', 'Whatever You Want', 'manage_options', 'my-menu' );
    add_submenu_page('my-menu', 'Submenu Page Title2', 'Whatever You Want2', 'manage_options', 'my-menu2' );
}
 

例

You can make the 'slug' for the submenu page equal that of the top level page, and they'll point to the same place:

add_action('admin_menu', 'my_menu_pages');
function my_menu_pages(){
    add_menu_page('My Page Title', 'My Menu Title', 'manage_options', 'my-menu', 'my_menu_output' );
    add_submenu_page('my-menu', 'Submenu Page Title', 'Whatever You Want', 'manage_options', 'my-menu' );
    add_submenu_page('my-menu', 'Submenu Page Title2', 'Whatever You Want2', 'manage_options', 'my-menu2' );
}

E.g.

親メニュー項目とサブメニューのスラッグを以下のように同じ(最初の1項目)にします

 function acutions_recent_bids_add_admin_page(){

add_menu_page('Recent Bids', 'Auction Reports', 'manage_options','wc-auction-reports','acutions_recent_bids_list','dashicons-chart-area', 56);   

add_submenu_page(
    'wc-auction-reports',       // parent slug
    'Recent Bids',    // page title
    'Recent Bids',             // menu title
    'manage_options',           // capability
    'wc-auction-reports', // slug
    'acutions_customers_spendings_list' // callback
); 


add_submenu_page(
    'wc-auction-reports',       // parent slug
    'Customer Spending',    // page title
    'Customer Spending',             // menu title
    'manage_options',           // capability
    'wc-acutions-customers-spendings', // slug
    'acutions_customers_spendings_list' // callback
); 

add_submenu_page(
    'wc-auction-reports',       // parent slug
    'Customer Bids',    // page title
    'Customer Bids',             // menu title
    'manage_options',           // capability
    'wc-acutions-customers-bids', // slug
    'acutions_customers_bids_list' // callback
);  

}

add_action('admin_menu','acutions_recent_bids_add_admin_page'); 
 

make the slug of parent menu item and sub menu same (first one item) like below

function acutions_recent_bids_add_admin_page(){

add_menu_page('Recent Bids', 'Auction Reports', 'manage_options','wc-auction-reports','acutions_recent_bids_list','dashicons-chart-area', 56);   

add_submenu_page(
    'wc-auction-reports',       // parent slug
    'Recent Bids',    // page title
    'Recent Bids',             // menu title
    'manage_options',           // capability
    'wc-auction-reports', // slug
    'acutions_customers_spendings_list' // callback
); 


add_submenu_page(
    'wc-auction-reports',       // parent slug
    'Customer Spending',    // page title
    'Customer Spending',             // menu title
    'manage_options',           // capability
    'wc-acutions-customers-spendings', // slug
    'acutions_customers_spendings_list' // callback
); 

add_submenu_page(
    'wc-auction-reports',       // parent slug
    'Customer Bids',    // page title
    'Customer Bids',             // menu title
    'manage_options',           // capability
    'wc-acutions-customers-bids', // slug
    'acutions_customers_bids_list' // callback
);  

}

add_action('admin_menu','acutions_recent_bids_add_admin_page'); 

これを追加するだけです:

 $submenu['my-menu'][0][0] = 'My New Menu Title';
 

デバッグの目的で、print_r($menu)を実行してWPメニュー全体を確認できます.

Simply add this:

$submenu['my-menu'][0][0] = 'My New Menu Title';

For debugging purposes, you can do a print_r($menu) to check the whole WP menu.

 add_submenu_page(
        'tut_theme_settings',       // parent slug
        'Front Page Elements 2',    // page title
        'Front Page 2',             // menu title
        'manage_options',           // capability
        'tut_theme_settings2',      // slug
        'theme_front_page_settings' // callback
    ); 
 

最初のサブメニューの名前が異なる場合は、親と最初の子の同じスラッグを作成し、同じ関数を呼び出します

add_submenu_page(
        'tut_theme_settings',       // parent slug
        'Front Page Elements 2',    // page title
        'Front Page 2',             // menu title
        'manage_options',           // capability
        'tut_theme_settings2',      // slug
        'theme_front_page_settings' // callback
    ); 

if different name of first sub-menu create same slug of parent and first child and call same function