master.xml

<data>
  <url-segments>
    <segment>firstlink</segment>
    <segment>2ndlink</segment>
    <segment>thirdlink</segment>
    <segment>4thlink</segment>
    <segment>?poop=4thlink</segment>
  </url-segments>
</data>

master.xsl

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

  <xsl:template match="/">
    <xsl:apply-templates select="//data/url-segments" mode="breadcrumb"/>
  </xsl:template>

  <xsl:template match="//data/url-segments" mode="breadcrumb">
		<xsl:apply-templates select="segment" mode="breadcrumb"/>	
	</xsl:template>

  <xsl:template match="segment" mode="breadcrumb">
		<xsl:param name="base-url" select="'/'"/>
		<xsl:param name="this-segment-url" select="concat($base-url, ., '/')" />
            <xsl:variable name="url">

<xsl:for-each select="preceding-sibling::*"><xsl:value-of select="."/><xsl:text>/</xsl:text></xsl:for-each>
<xsl:value-of select="."/>
</xsl:variable>
                   	<a><xsl:attribute name="href"><xsl:value-of select="$url"/></xsl:attribute><xsl:value-of select="." /></a>
          		<xsl:apply-templates select="segment" mode="breadcrumb">
                            <xsl:with-param name="base-url" select="$this-segment-url" />
                    	</xsl:apply-templates>
	</xsl:template>


</xsl:stylesheet>