Specify which categories appear in filter navigation

hi,

I have about 20 categories but only want my users to be able to filter by 5 of those 20 categories. Can i somehow limit which categories appear in the filter menu?

I’ve been looking at this code in the head.php

<?php if(is_page()): ?>
<nav id="primary-nav">
  <div class="container">
  <a href="#">show/hide</a>
  <div class="columns sixteen">
    <div class="nav-label"><?php _e('Filter By:','sampression'); ?></div>

    <ul class="nav-listing clearfix">

<li><a href="#"><span></span><?php _e('Show All','sampression'); ?></a></li>
        <?php
        $categories = get_categories();
        foreach($categories as $category):
        ?>

<li><a href="void(0);">slug; ?>" id="<?php echo $category->slug; ?>" class="filter-data"><span></span><?php echo $category->name; ?></a></li>
        <?php
        endforeach;
        ?>

I suspect it has something to do with <?php echo $category->name; ?>