You need a simple navigation for your single HTML file. The navigation should contain for each chapter a link to the next and previous chapters including an up link pointing to the enclosing part or book. This is depicted in the following graphic:

The following file defines the named template generate.simple.navigation:

<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:d="http://docbook.org/ns/docbook"
  xmlns="http://www.w3.org/1999/xhtml"
  exclude-result-prefixes="d">
    
  <xsl:template name="generate.simple.navigation">
    <xsl:param name="node" select="."/>
    <xsl:variable name="prev" select="$node/preceding-sibling::d:chapter"/>
    <xsl:variable name="next" select="$node/following-sibling::d:chapter"/>
    <xsl:variable name="up"   select="$node/parent::d:*"/>
   
    <div class="chapter-navigation">
      <ul>
        <xsl:if test="count($next) >0">
          <li class="next">
            <xsl:call-template name="gentext.nav.next"/>
            <xsl:text>: </xsl:text>
            <a>
              <xsl:attribute name="href">
                <xsl:call-template name="href.target">
                  <xsl:with-param name="object" select="$next"/>
                </xsl:call-template>
              </xsl:attribute>
              <xsl:value-of select="$next/d:title"/>
            </a>
          </li>
        </xsl:if>
        <xsl:if test="count($prev) >0">
          <li class="prev">
            <xsl:call-template name="gentext.nav.prev"/>
            <xsl:text>: </xsl:text>
            <a>
              <xsl:attribute name="href">
                <xsl:call-template name="href.target">
                  <xsl:with-param name="object" select="$prev"/>
                </xsl:call-template>
              </xsl:attribute>
              <xsl:value-of select="$prev/d:title"/>
            </a>
          </li>
        </xsl:if>
        <xsl:if test="count($up) >0">
          <li class="up">
            <xsl:call-template name="gentext.nav.up"/>
            <xsl:text>: </xsl:text>
            <a>
              <xsl:attribute name="href">
                <xsl:call-template name="href.target">
                  <xsl:with-param name="object" select="$up"/>
                </xsl:call-template>
              </xsl:attribute>
              <xsl:value-of select="$up/d:title"/>
            </a>
          </li>
        </xsl:if>
      </ul>
    </div>
  </xsl:template>
</xsl:stylesheet>

This is not enough, of course. Use the following steps to include it into your customization layers:

If you want to switch on or off the above behaviour, use the parameter generate.simple.navigation^[9] and set it to 0.

The named template generate.simple.navigation works as follows:

The generate.simple.navigation template matches only chapters along the sibling axis. As such it can not find a glossary or appendix after a chapter. If you want to create links for any component elements, not only chapters, you need to change the variables prev and next. A first attempt would lead to this:

<xsl:variable name="prev" select="$node/preceding-sibling::d:*[1]"/>
<xsl:variable name="next" select="$node/following-sibling::d:*[1]"/>

This works for the next variables. However, our expression for the prev variable contains a bug. Consider the following structure:

book
  title
  info
  chapter
  ...

The preceding-sibling axis returns the info and title elements. This is not what you want as these are no component elements for our prev link. In that case we need an expression to filter out the unwanted elements. This is done with an predicate:

<xsl:variable name="prev" select="$node/preceding-sibling::d:*[not(self::d:title|self::d:info)][1]"/>

That expression first creates a node set with all preceding elements. In a second step they are check against the term not(self::d:title|self::d:info); only those elements remain in the node set which are not title or info elements. In our above example, this leads to a node set with zero nodes and is exactly what we wanted to achieve.

With the previous change, we allow any structural element to be included in a next or previous link. However, we show our navigation links only in chapter titlepages at the moment (the named template chapter.titlepage.before.recto.) We need to extend the stylesheet db-simple-navigation.xsl to allow elements like appendix, glossary, etc. Refer to the content modell of DocBook´s book element for details. For an appendix this looks like this:

<xsl:template name="appendix.titlepage.before.recto">
  <xsl:if test="$generate.simple.navigation != 0">
    <xsl:call-template name="generate.simple.navigation"/>
  </xsl:if>
</xsl:template>

For the other elements this is exactly the same except the name. Just use the element name and append .titlepage.before.recto.