two level grouping

Hi there,

I am trying to create an index of keywords of my online-book.
My source XML-file contains a lot of keywords which are more specified with
Elements (Level1 or even Level2):

<Stichwortliste>
<Stichwortdetails>
        <Stichwort>
                <Level1>ius civile</Level1>
                <Titel titel_id="CBAHDGEI">Bürgerliches Recht, Zivilrecht,
ius civile</Titel>
                <Kapitel>kap1_1.xml</Kapitel>
        </Stichwort>
        <Stichwort>
                <Level1>Privatrecht</Level1>
                <Titel titel_id="CBAHDGEI">Bürgerliches Recht, Zivilrecht,
ius civile</Titel>
                <Kapitel>kap1_1.xml</Kapitel>
        </Stichwort>
        <Stichwort>
                <Level1>Privatrecht</Level1>
                <Level2>allgemeines</Level2>
                <Titel titel_id="CBAHDGEI"> Recht im objektiven und
subjektiven Sinn</Titel>
                <Kapitel>kap2_4.xml</Kapitel>
        </Stichwort>
        <Stichwort>
                <Level1>Privatrecht</Level1>
                <Titel titel_id="CBAHDGEI"> Das Gesamtrechtssystem </Titel>
                <Kapitel>kap5_3.xml</Kapitel>
        </Stichwort>
</Stichwortdetails>
<Stichwortliste>


I would like to have the following output:

The keywords are sorted alphabetically and if there are more keywords that
are equal the name of the keyword should be printed once and the
chapter-specifications should follow. And if there are keywords that own the
more specified Level2 then these keywords (+chapter-specifications) should
not be given out until all the keywords (only with Level1-elements of the
same name) have been printed out.

Here is what I have:

I
ius civile [kap1_1]

P
Privatrecht [kap1_1],
        allgemeines [kap2_4], [kap5_3]


Here is what I would like to have:

I
Ius civile [kap1_1]

P
Privatrecht [kap1_1], [kap5_3]
        allgemeines [kap2_4]


Here is my XSL:

<xsl:key name="keyword-initial" match="Stichwort"
use="translate(substring(Level1,1,1),'abcdefghijklmnopqrstuvwxyzäöü123456789
0@','ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÜ###########')"/>
<xsl:key name="contacts-by-surname" match="Stichwort" use="Level1"/>
<xsl:template match="Stichwortdetails">
        
        <xsl:for-each select="Stichwort[count(. | key('keyword-initial',
translate(substring(Level1,1,1), 'abcdefghijklmnopqrstuvwxyzäöü1234567890@',
'ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÜ###########'))[1]) = 1]">
                <xsl:sort select="Level1"/>
                <xsl:variable name="initial"
select="translate(substring(Level1,1,1),
'abcdefghijklmnopqrstuvwxyzäöü1234567890@',
'ABCDEFGHIJKLMNOPQRSTUVWXYZÄÖÜ###########')"/>
                <a name="{$initial}"/>
                        <div><xsl:value-of select="$initial"/></div>
                        <ul>
                                <xsl:for-each select="key('keyword-initial',
$initial)">
                                        <xsl:sort select="Level1"/>
                                        <xsl:if test="count(. |
key('contacts-by-surname', Level1)[1]) = 1">
                                                <br/>
                                                <span><xsl:value-of
select="Level1"/></span>
                                        </xsl:if>
                                                    <xsl:if
test="not(name(Level1/following-sibling::*) = 'Level2')">
                                                        <span
style="color:green;"><xsl:apply-templates select="Level1"
mode="index.link"/></span>
                                                    </xsl:if>
                                    <xsl:for-each select="Level2">
                                                <xsl:sort select="Level2"/>
                                                <br/>
                                                <span style="color:red;
margin-left:20px;"><xsl:apply-templates select="."
mode="index.link"/></span>
                                        </xsl:for-each>             
                                </xsl:for-each>
                        </ul>
                        <br/>
        </xsl:for-each>
</xsl:template>


It seems that the second for-each-loop <xsl:for-each select="Level2"> isn’t
correct, but I don’t know how to do it right. 
It must be something like a grouping within a grouping?!?
Can you give me any advice?

Thanks
Martina