这应该让你开始。如果您已经阅读了文档（您应该阅读这些文档），那么其余的内容就不言自明了。

$array = array(
    array(
        'id' => '1',
        'menu' => 'Oil',
        'submenu' => 'editable',
        'childmenu' => 'coco oil'
    ),
    array(
        'id' => '2',
        'menu' => 'Oil',
        'submenu' => 'editable',
        'childmenu' => 'sunflower'
    ),
    array(
        'id' => '3',
        'menu' => 'Oil2',
        'submenu' => 'noneditable',
        'childmenu' => 'deepa'
    ),
);
// CONTROLLER
$_data = array();
// $array will come from model result_array()
foreach ($array as $item) {
    $_data[$item['menu']][$item['submenu']][] = $item['childmenu'];
}
// send $_data to view
// VIEW
foreach ($_data as $menu => $submenu) {
    echo '<i>' . $menu . '</i><br>';
    foreach ($submenu as $name => $childmenu) {
        echo '<strong>' . $name . '</strong><br>';
        foreach ($childmenu as $item) {
            echo $item . '<br>';
        }
    }
}

基本上，我重新安排了数组，使其更易于使用。这样就避免了我们以后在视图中检查foreach中的特定子菜单。