bid/module/Admin/view/navigation/left-side.phtml

<!-- 
-->
<?php
/**
 * left navigation view partial
 * should only be called by the navigation view helper
 *
 * labels are already translated in page class
 *
 */
$counter = 0;
?>
<div class="sidebar">
    <ul class="nav nav-list">
        <li class="nav-header">
            <?php if (isset($this->menu->icon)) { ?>
                <i class="<?php echo $this->menu->icon; ?>"></i>
            <?php } ?>
            <?php echo $this->menu->label; ?>
        </li>
        <?php foreach ($this->menu->pages as $key => $page) { ?>
            <?php if ($page->hidden != 'true' && $page->filter != 'true' && $this->navigation()->accept($page)) { ?>
                <?php
                $class = array();
                $mainMenuActive = false;
                $activeAccordion = '';

                if ($page->isActive(true)) {
                    $class[] = 'active';
                    $mainMenuActive = true;
                }
                if (!empty($page->pages) && $page->hidden_children != 'true') {
                    $class[] = 'accordion-menu';

                    foreach ($page->pages as $subPage) {
                        if ($subPage->isActive(true)) {
                            $activeAccordion = 'in';

                            if (!$mainMenuActive) {
                                $class[] = 'active';
                            }
                        }

                        if (!empty($subPage->pages)) {
                            foreach ($subPage->pages as $subSubPage) {
                                if ($subSubPage->isActive(true)) {
                                    $activeAccordion = 'in';

                                    if (!$mainMenuActive) {
                                        $class[] = 'active';
                                    }
                                }
                            }
                        }
                    }
                }
                ?>
                <li <?php echo (count($class) > 0) ? 'class="' . implode(' ', $class) . '"' : ''; ?>>
                    <a <?php echo (!empty($page->pages) && $page->hidden_children != 'true') ?
                        'href="#' . $counter . '" data-toggle="collapse" class="accordion-toggle"' : 'href="' . $this->url($page->params) . '"'; ?>>
                <span>
                    <?php echo $page->label; ?>
                    <?php if (!empty($page->pages) && $page->hidden_children != 'true') { ?>
                        <i class="fa fa-chevron-down pull-right"></i>
                    <?php } ?>
                </span>
                    </a>

                    <?php if (!empty($page->pages) && $page->hidden_children != 'true') { ?>
                        <div class="accordion-body collapse <?php echo $activeAccordion; ?> dropdown"
                             id="<?php echo $counter++; ?>">
                            <div class="accordion-inner">
                                <ul class="nav nav-list">
                                    <?php
                                    foreach ($page->pages as $subKey => $subPage) {
                                        if ($subPage->hidden != 'true' && $this->navigation()->accept($subPage)) {
                                            $class = array();
                                            $mainMenuActive = false;
                                            $activeAccordion = '';

                                            if ($subPage->isActive(true)) {
                                                $class[] = 'active';
                                                $mainMenuActive = true;
                                            }
                                            if (!empty($subPage->pages)) {
                                                $class[] = 'accordion-menu';

                                                foreach ($subPage->pages as $subSubPage) {
                                                    if ($subSubPage->isActive(true)) {
                                                        $activeAccordion = 'in';

                                                        if (!$mainMenuActive) {
                                                            $class[] = 'active';
                                                        }
                                                    }
                                                }
                                            }
                                            ?>


                                            <li <?php echo (count($class) > 0) ? 'class="' . implode(' ',
                                                    $class) . '"' : ''; ?>>
                                                <a <?php echo (!empty($subPage->pages) && $subPage->hidden != 'true') ?
                                                    'href="#' . $counter . '" data-toggle="collapse" class="accordion-toggle"' : 'href="' . $this->url($subPage->params) . '"'; ?>>
                                                    <span><?php echo $subPage->label; ?></span>
                                                    <?php if (!empty($subPage->pages)) { ?>
                                                        <i class="fa fa-chevron-down pull-right"></i>
                                                    <?php } ?>
                                                </a>

                                                <?php if (!empty($subPage->pages)) { // here the hidden tag wont work ?>
                                                    <div
                                                        class="accordion-body collapse <?php echo $activeAccordion; ?> dropdown"
                                                        id="<?php echo $counter++; ?>">
                                                        <div class="accordion-inner">
                                                            <ul class="nav nav-list">
                                                                <?php foreach ((array)$subPage->pages as $subSubPage) { ?>
                                                                    <?php if ($this->navigation()->accept($subSubPage)) { ?>
                                                                        <li <?php echo ($subSubPage->isActive(true)) ? 'class="active"' : ''; ?>>
                                                                            <a href="<?php echo $this->url($subSubPage->params); ?>"><?php echo $subSubPage->label; ?></a>
                                                                        </li>
                                                                    <?php } ?>
                                                                <?php } ?>
                                                            </ul>
                                                        </div>
                                                    </div>
                                                <?php } ?>
                                            </li>
                                        <?php
                                        }
                                    } ?>
                                </ul>
                            </div>
                        </div>
                    <?php } ?>
                </li>

            <?php } ?>
        <?php } ?>
    </ul>
</div>