<root>
-<node>
- <ID1> 1</ID1>
- <ID2> 1</ID2>
- <ID3> 1</ID3>
-</node>
-<node>
- <ID1> 1</ID1>
- <ID2> 2</ID2>
- <ID3> 1</ID3>
-</node>
</root>

<xsl:key name="key1" match="/root/node" use="ID1/text()" />
 <xsl:key name="key2" match="/root/node" use="concat(ID1/text(),ID2/text())" />
 <xsl:key name="key3" match="/root/node" use="concat(ID1/text(),ID2/text(),ID3/text())" />

  <xsl:for-each select="/root/node[generate-id()=generate-id(key('key1',ID1/text()))]">
   <xsl:variable name="poz" select="ID2" />
	<xsl:for-each select="/root/node[generate-id()=generate-id(key('key2'', concat($poz,ID2/text())))]">
                 <xsl:variable name="poz1" select="ID3" />
                        <xsl:for-each select="/root/node[generate-id()=generate-id(key('key3'', concat($poz,$poz1,ID3/text())))]">
                                    ...
                        </xsl:for-each> 
           </xsl:for-each> 
   </xsl:for-each>