只需创建一个“占位符”菜单，即可将所有帖子类型分配给：

function wpse_226690_admin_menu() {
    add_menu_page(
        \'Events Manager\',
        \'Events Manager\',
        \'read\',
        \'events-manager\',
        \'\', // Callback, leave empty
        \'dashicons-calendar\',
        1 // Position
    );
}

add_action( \'admin_menu\', \'wpse_226690_admin_menu\' );

\'show_in_menu\' => \'events-manager\',