Question

How I can find with Xsl all the node that have then name like the value of an other node
Like these:

 <root>
    <data1>
      <subdata1>
        ...
        <selectThese></selectThese>
        ...
      </subdata1>

    </data1>
    <nodesetFind>
      <node1>selectThese</node1>
    </nodesetFind>
  </root>

the result: <selectThese></selectThese>

Answer 1

Use:

/*/data1//*[name() = /*/nodesetFind/*]

Demonstrated in an XSLT transformation:

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

 <xsl:output omit-xml-declaration="yes" indent="yes"/>
 <xsl:template match="/">
  <xsl:copy-of select="/*/data1//*[name() = /*/nodesetFind/*]"/>
 </xsl:template>
</xsl:stylesheet>

when this transformation is applied on the provided XML document:

<root>
    <data1>
      <subdata1>
        ...
        <selectThese></selectThese>
        ...
      </subdata1>

    </data1>
    <nodesetFind>
      <node1>selectThese</node1>
    </nodesetFind>
  </root>

the wanted, correct result is produced:

<selectThese></selectThese>