You can use DITA2Go-supplied navigation macros to create a browse-type navigation system in HTML, with previous and next links connecting all files in a single bidirectional series:
<$_prev> for a link to the preceding HTML file
<$_next> for a link to the following HTML file.
DITA2Go also provides predefined macro <$_top> for a jump to top-of-page.
§29.3.1 Understanding how browse macros work
§29.3.2 Choosing buttons versus text links for a browse sequence
§29.3.3 Formatting browse-link labels
§29.3.4 Modifying macros <$_prev>, <$_next>, and <$_top>
§29.3.5 Understanding browse keyword scope and default values
§29.3.6 Specifying where to invoke a browse macro