...............
<segment Id="LOC">
<element Id="LOC01"> 42 </element>
<element Id="LOC02" Composite="yes">
<subelement Id="LOC02" Composite="yes" Sequence="1"> 22399201 </subelement>
</element>
</segment>
..................
<segment Id="LOC">
<element Id="LOC01"> 42 </element>
<element Id="LOC02" Composite="yes">
<subelement Id="LOC02" Composite="yes" Sequence="1"> 22777777 </subelement>
<subelement Sequence="2"> 37 </subelement>
</element>
</segment>
................

NodeIterator TEST = XPathAPI.selectNodeIterator(documentSource,"//transaction/segment[@Id='LOC' and element[@Id='LOC01']='42']/element[@Id='LOC02']/subelement[@Id='LOC02']/text()"); 
Node test;
         while  ((test = TEST.nextNode())!= null )
        {
           Test = test.getNodeValue();
           Test_42 = Test.substring( 0 , 2 );
                      
            if  (Integer.parseInt(Test_42) ==  22  )
           {
              System.out.println("nom_pp = " + n + " Test = " + (Test.substring( 2 )));
              n++;
           }
}

nom_pp =  0  Test =  399201 
nom_pp =  1  Test =  405050 
nom_pp =  2  Test =  7777777