Show Navigation Option to Certain Groups in Social Engine

Modify the file application/modules/Core/widgets/menu-main/index.tpl

Replace this:

echo $this->navigation()
->menu()
->setContainer($this->navigation)
->setPartial(null)
->render();

With this:

<ul>
<?php
foreach( $this->navigation->getPages() as $item);
?>
<?php foreach( $this->navigation as $item ): ?>
<li><?php echo $this->htmlLink($item->getHref(), $this->translate($item->getLabel()), array_filter(array(
'class' => ( !empty($item->class) ? $item->class : null ),
'alt' => ( !empty($item->alt) ? $item->alt : null ),
'target' => ( !empty($item->target) ? $item->target : null ),
))) ?></li>
<?php endforeach;
$table = Engine_Api::_()->getDbtable('users', 'user');
$select = $table->select() ->where("user_id = '".$this->viewer()->getIdentity()."' AND level_id = '1'");
echo count($table->fetchAll($select)) ? '<li><a href="#">Navigation Option</a></li>' : "; // If user belongs to level 1
?>
</ul>

This will be improved on in due course once I understand the system some more