show header options when 2 users are logged in

I want to make an if isset statement so when a user logs in it must show all the options in the header. It works but I want it for 2 users.

This is how the header looks like right now:

<?php if(isset($_SESSION['werknemer_level']) && $_SESSION['werknemer_level'] == 1): ?> 
            <li> <a href="">Uitgeplaatste jongeren</a> </li>
            <li> <a href="">Ingeschreven jongeren</a> </li> 
            <li> <a href="">Leeftijd jongeren</a> </li> 
            <li> <a href="">Jongeren activiteiten</a> </li> 
            <li> <a href="Auth/logout">Uitloggen</a> </li> 
            <?php endif;?>

So as you can see the header options are only showing when a 'werknemer' is logged in. I have 2 kind of users that are able to login. 1= werknemer 2= administrator

I want both users to see those options in the header but I don't know how to do that.

For both users I created the same sessions:

$_SESSION['administrator_level'] = 1; 
$_SESSION['werknemer_level'] = 1; 

I tried doing something like this: <?php if(isset($_SESSION['werknemer_level']) && $_SESSION['administrator_level'] == 1): ?> But it doesn't work like that. Hope someone can help me. Any kind of help is appreciated