core-bundle/src/Resources/contao/modules/ModuleQuicknav.php
protected function getQuicknavPages($pid, $level=1, $host=null)
	{
		/** @var PageModel $objPage */
		global $objPage;

		$groups = array();
		$arrPages = array();

		// Get all groups of the current front end user
		if (FE_USER_LOGGED_IN)
		{
			$this->import(FrontendUser::class, 'User');
			$groups = $this->User->groups;
		}

		// Get all active subpages
		$objSubpages = PageModel::findPublishedRegularWithoutGuestsByPid($pid);

		if ($objSubpages === null)
		{
			return array();
		}

		++$level;

		foreach ($objSubpages as $objSubpage)
		{
			$_groups = StringUtil::deserialize($objSubpage->groups);

			// Override the domain (see #3765)
			if ($host !== null)
			{
				$objSubpage->domain = $host;
			}

			// Do not show protected pages unless a front end user is logged in
			if (!$objSubpage->protected || $this->showProtected || (\is_array($_groups) && \is_array($groups) && array_intersect($_groups, $groups)))
			{
				// Do not skip the current page here! (see #4523)

				// Check hidden pages
				if (!$objSubpage->hide || $this->showHidden)
				{
					$arrPages[] = array
					(
						'level' => ($level - 2),
						'title' => StringUtil::specialchars(StringUtil::stripInsertTags($objSubpage->pageTitle ?: $objSubpage->title)),
						'href' => $objSubpage->getFrontendUrl(),
						'link' => StringUtil::stripInsertTags($objSubpage->title),
						'active' => ($objPage->id == $objSubpage->id || ($objSubpage->type == 'forward' && $objPage->id == $objSubpage->jumpTo))
					);

					// Subpages
					if (!$this->showLevel || $this->showLevel >= $level || (!$this->hardLimit && ($objPage->id == $objSubpage->id || \in_array($objPage->id, $this->Database->getChildRecords($objSubpage->id, 'tl_page')))))
					{
						$subpages = $this->getQuicknavPages($objSubpage->id, $level);

						if (\is_array($subpages))
						{
							$arrPages = array_merge($arrPages, $subpages);
						}
					}
				}
			}
		}

		return $arrPages;
	}
protected function getQuicknavPages($pid, $level=1, $host=null)
	{
		/** @var PageModel $objPage */
		global $objPage;

		$groups = array();
		$arrPages = array();

		// Get all groups of the current front end user
		if (FE_USER_LOGGED_IN)
		{
			$this->import(FrontendUser::class, 'User');
			$groups = $this->User->groups;
		}

		// Get all active subpages
		$objSubpages = PageModel::findPublishedRegularWithoutGuestsByPid($pid);

		if ($objSubpages === null)
		{
			return array();
		}

		++$level;

		foreach ($objSubpages as $objSubpage)
		{
			$_groups = StringUtil::deserialize($objSubpage->groups);

			// Override the domain (see #3765)
			if ($host !== null)
			{
				$objSubpage->domain = $host;
			}

			// Do not show protected pages unless a front end user is logged in
			if (!$objSubpage->protected || $this->showProtected || (\is_array($_groups) && \is_array($groups) && array_intersect($_groups, $groups)))
			{
				// Do not skip the current page here! (see #4523)

				// Check hidden pages
				if (!$objSubpage->hide || $this->showHidden)
				{
					$arrPages[] = array
					(
						'level' => ($level - 2),
						'title' => StringUtil::specialchars(StringUtil::stripInsertTags($objSubpage->pageTitle ?: $objSubpage->title)),
						'href' => $objSubpage->getFrontendUrl(),
						'link' => StringUtil::stripInsertTags($objSubpage->title),
						'active' => ($objPage->id == $objSubpage->id || ($objSubpage->type == 'forward' && $objPage->id == $objSubpage->jumpTo))
					);

					// Subpages
					if (!$this->showLevel || $this->showLevel >= $level || (!$this->hardLimit && ($objPage->id == $objSubpage->id || \in_array($objPage->id, $this->Database->getChildRecords($objSubpage->id, 'tl_page')))))
					{
						$subpages = $this->getQuicknavPages($objSubpage->id, $level);

						if (\is_array($subpages))
						{
							$arrPages = array_merge($arrPages, $subpages);
						}
					}
				}
			}
		}

		return $arrPages;
	}
Recursively get all quicknav pages and return them as array

@param integer $pid
@param integer $level
@param string  $host

@return array