CodeIgniter：下拉列表中的下拉列表

Question

Image of the navigation bar “用户”应该是一个下拉列表。子菜单是它下面的子菜单

  

这是我的代码。如何在第二个条件下进行DROPWDOWN DROPDOWN？ （其他部分）

<ul class="nav navbar-nav">
                <?php
                    foreach ($nav as $item) {
                        if (empty($item['children'])) {
                        ?>
                                <li<?php if (!empty($item['is_active'])) { ?> class="active"<?php } ?>>
                                <a href="<?php echo $item['link']; ?>"><?php if ($item['icon'] != '') { ?>
                                <i class="<?php echo $item['icon']; ?>" data-toggle="tooltip" data-placement="bottom" data-original-title="A large tooltip."></i>&nbsp; <?php } echo $item['label']; ?></a></li>
                        <?php
                        }
                        elseif (!empty($item['children']) && empty($item['children/'])) {
                                ?>
                                    <li class="dropdown <?php if (empty($item['children'])) { ?> active<?php } ?>">
                                        <a href="#" class="dropdown-toggle" data-toggle="dropdown" data-hover="dropdown">
                                            <?php if ($item['icon'] != '') { ?>
                                                <i class="<?php echo $item['icon']; ?>"></i>
                                            &nbsp;<?php  echo $item['label']; ?>
                                            <b class="caret"></b><?php } ?>
                                        </a>

                                        <ul class="dropdown-menu scrollable-menu" role="menu"> 
                                    <?php
                                                _main_menu_widget_display_children($item['children']);
                                    ?>


                                        </ul>
                                    </li>
                                <?php
                         }
                        else 
                        {
                        ?>
                            <li class="dropdown <?php if (!empty($item['is_active'])) { ?> active<?php } ?>">
                                <a href="#" class="dropdown-toggle" data-toggle="dropdown" data-hover="dropdown">
                                    <?php if ($item['icon'] != '') { ?>
                                        <i class="<?php echo $item['icon']; ?>"></i>
                                    &nbsp;<?php  echo $item['label']; ?>
                                    <b class="caret"></b><?php } ?>
                                </a>

                                <ul class="dropdown-menu scrollable-menu" role="menu"> 
                            <?php
                                        _main_menu_widget_display_children($item['children']);
                            ?>


                                </ul>
                            </li>
                        <?php                   
                        }
                }               
            ?>              
                </ul>