Maps with Map Hierarchy
A map with a map hierarchy is created by nesting maps within each other.
Example
<map id="_m_user_guide" title="User Guide">
<mapref href="_m_topic_editor.ditamap" />
<mapref href="_m_map_editor.ditamap" />
</map>Considerations
Map titles do not display as headings. When published, there is no visual hierarchy created to distinguish between map levels so it looks flat. To resolve this, you can add navigational headings for each map title. For more information, see Navigational Headings.