The Hierarchy Navigator page allows you to browse through a hierarchy.
The bread-crumb list (1) shows the path to the current node in the hierarchy. All ancestors of the current node are shown as a link which if clicked on will navigate up to that ancestor and show its children.
The child list (2) shows a list of the children of the current node. The list size can be modified with the drop-down selector and long lists can be paged through. Child topics that themselves have children in the hierarchy are shown as a link which if clicked on will navigate down to that child node and show its children. Each child node also has a 
button which if clicked will take you to the Topic Page for that topic.
At any point you can return to the Topic Map Home Page by clicking on the orange link in the page header.