Hello,
Here is my XML:
<table>
   <data>
        <form uuid="7eb088d0-e307-4901-aa21-d3cdd7c6823b">
            <field ref="label">Label add Tag1</field>
            <field ref="description">Adding a Task for Tag1</field>
            <field ref="tag">TAG1</field>
        </form>
        <form uuid="8f289097-6164-4398-ba0a-115c4edb5fec">
            <field ref="label">Label added</field>
            <field ref="description">Adding a Task for Tag2</field>
            <field ref="tag">TAG2</field>
           </form>
        <form uuid="54faebbd-c80c-4411-868f-019be6a06198">
            <field ref="label">One more Label</field>
            <field ref="description">Adding a Task for Tag3</field>
            <field ref="tag">TAG3</field>
         </form>
     <form uuid="54faebbd-c80c-4411-868f-019be6a06198">
            <field ref="label">One more Label in Tag 2</field>
            <field ref="description">Adding a Task Tag2</field>
            <field ref="tag">TAG2</field>
         </form>
    </data>
  </table>

My XSL:
    <xsl:key name="filter-by-label" match="table/data/form" use="field[@ref='tag']" />
<xsl:for-each select="table/data/form[generate-id() = generate-id(key('filter-by-label', field[@ref='tag']))]">
                <b><xsl:value-of select="field[@ref='tag']" /></b> <br />
                <xsl:for-each select="key('filter-by-label', field[@ref='tag'])">
                    -- <xsl:value-of select="//@ref='label'"/>
                </xsl:for-each>
            </xsl:for-each>



I would like to Group the Result like this:
 TAG1
    - Adding a Task for Tag1
 TAG2
    - Adding a Task for Tag2
    - One more Label in Tag 2
 TAG3
    - Adding a Task for Tag3

I am not sure how to retrieve the result like shown above.

I really appreciate your help.

Thanks,
Vin

I don't understand why your specimen output for TAG2 includes the label field of one of the forms, and the description field of another. Assuming you always want to output the description, use

<xsl:value-of select="field[@ref='description']"/>

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Thanks Mr.Kay. Forgive my typo. When I reconstruct it from the original data, I misplaced the data. But looks like this logic is fine but I had to fix outer loop in my original code.

Thanks again,
Vin