XSL Stylesheet

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                version="2.0">

<xsl:output method="xhtml" indent="yes"/>

<xsl:template match="/">
  <html>
    <head>
      <title>Grouping By Starting Value</title>
    </head>
    <body>
      <xsl:apply-templates/>
    </body>
  </html>
</xsl:template>

<xsl:template match="body">

<xsl:for-each-group select="*" group-starting-with="h1">
  <div>
    <xsl:apply-templates select="current-group()"/>
  </div>
</xsl:for-each-group>

</xsl:template>

<xsl:template match="*">
  <xsl:copy>
    <xsl:copy-of select="@*"/>
    <xsl:apply-templates/>
  </xsl:copy>
</xsl:template>

</xsl:stylesheet>