List of unique attribute values ​​within a group only for certain criteria in XSL 1.0

I need to provide unique values ​​for an attribute in a group when another attribute has a specific value. Making this work in XSL 1.0 is very difficult to understand.

Thanks to another post, I now have groups that allow me to do a count when attributes meet certain criteria. However, I cannot say that I can only specify unique values ​​for one specific attribute, where the other attribute is equal to a specific value, but only within the members of the current group.

As always, this will make more sense with examples of source data and code.

Here is an example XML

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Group1>
  <Group2>
    <LocationIdentification LocationID="0610390" />
    <LocationIdentification1 LocationQualifier="12" LocationID="USLGB"/>
  </Group2>
  <Group2>
    <LocationIdentification LocationID="0610612" />
    <LocationIdentification1 LocationQualifier="12" LocationID="USLAX"/>
  </Group2>
  <Group2>
    <LocationIdentification LocationID="0650004"/>
    <LocationIdentification1 LocationQualifier="12" LocationID="USLGB"/>
  </Group2>
  <Group2>
    <LocationIdentification LocationID="0650306"/>
    <LocationIdentification1 LocationQualifier="6" LocationID="USLAX"/>
   </Group2>
   <Group2>
    <LocationIdentification LocationID="0650220"/>
    <LocationIdentification1 LocationQualifier="12" LocationID="USLGB"/>
   </Group2>
</Group1>

      

        
        
        
      

    

I have an XSL to create groups based on the first three characters of the LocationID attribute from the LocationIdentification node.

XSL 1.0

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

<xsl:key name="grp" match="Group2" use="substring(LocationIdentification/@LocationID, 1, 3)"/>

<xsl:template match="/Group1">
<table align="center" border="1">
    <thead>
        <tr>
            <th>Bay</th>
            <th>Units</th>
            <th>Locations</th>
        </tr>
    </thead>
    <tbody>
        <xsl:for-each select="Group2[generate-id()=generate-id(key('grp', substring(LocationIdentification/@LocationID, 1, 3))[1])]">
            <xsl:sort select="LocationIdentification/@LocationID"/>
            <xsl:variable name="curr-key" select="substring(LocationIdentification/@LocationID, 1, 3)" />           
            <xsl:variable name="curr-group" select="key('grp', $curr-key)" />
            <tr>
                <td>
                    <xsl:value-of select="$curr-key"/>
                </td>
                <td>
                    <xsl:value-of select="count($curr-group)"/>
                </td>
                <td>
                <!-- NEW CODE NEEDS TO GO HERE -->
                </td>
            </tr>
        </xsl:for-each>
    </tbody>
</table>
</xsl:template>

</xsl:stylesheet>

      

        
        
        
      

    

I need to figure out how to list unique LocationID values ​​in LocationIdentification1 where LocationQualifier = '12 '

Desired result

<table align="center" border="1">
  <thead>
    <tr>
        <th>Bay</th>
        <th>Count</th>
        <th>Location(s)</th>
    </tr>
  </thead>
  <tbody>
   <tr>
    <td>061</td>
    <td>2</td>
    <td>USLGB USLAX</td>
  </tr>
  <tr>
    <td>065</td>
    <td>3</td>
    <td>USLGB</td>
  </tr>
</table>

      

        
        
        
      

    

Note that Bay 65 has a score of 3, but only 2 of them have a LocationQualifier of 12 and they both have the same value for the LocationID, so the output should only contain the USLGB list for locations.