The following creates a simple menu in HTML, based on the last 4 pages. Only pages where the chapter taxonomy is 'main' are selected, assuming there's a taxonomy 'chapter'.
<nav id="main">
{% setcontent pages = 'pages/latest/4' where { 'taxonomy/chapter': 'main'} %}
{% for page in pages %}
{% if loop.first %}<ul>{% endif %}
<li><a href="{{ page|link }}" {% if page|current %}class="current"{% endif %}>{{ page.title|trimtext(12) }}</a></li>
{% if loop.last %}</ul>{% endif %}
{% else %}
<em>No main navigation items. Add some Pages, and set the 'Chapter' to 'Main'.</em>
{% endfor %}
</nav>
Note: This is a specific sample. In general, you're probably better off using Bolt's built in menu functionality.