在按Buddy键的情况下，向父菜单项添加子导航菜单项时遇到问题。

父菜单项如下所示，名为TEST, 正确显示，但名为SUB NAV 和SUB NAV 2 根本不显示。

function my_setup_nav() { 
global $bp; 
$em_link = $bp->loggedin_user->domain . $bp->account->slug . \'/\';

# - add parent menu item    

bp_core_new_nav_item( array( 
    \'name\' =>  \'TEST\',
    \'slug\' =>  $bp->account->slug, 
    \'position\' => 10,
    ) 
); 

# - add sub nav menu items

bp_core_new_subnav_item( array( 
    \'name\' => \'SUB NAV\',
    \'slug\' => \'account-sub\', 
    \'parent_url\' =>  $em_link ,
    \'parent_slug\' => $bp->account->slug,
    \'position\' => 10,
    \'item_css_id\' => \'xx\' 
    ) 
); 
bp_core_new_subnav_item( array( 
    \'name\' => \'SUB NAV 2\',
    \'slug\' => \'account-sub-2\', 
    \'parent_url\' =>  $em_link ,
    \'parent_slug\' => $bp->account->slug,
    \'position\' => 20,
    \'item_css_id\' => \'xx-2\' 
    ) 
); 
} 

add_action( \'bp_setup_nav\', \'my_setup_nav\', 99 );