Read Complex XML in LINQ

<Controls version="1.0">
  <ContentsTypes>
    <ContentType Id="DOCUMENT_SOC" Value="Document société">
      <SecretsLevels>
        <SecretLevel label="Confidentiel">100</SecretLevel>
        <SecretLevel label ="Public">500</SecretLevel>
      </SecretsLevels>
        <Index>
          <Control>
            <Id>1</Id>
            <Code>NOM</Code>
            <Type>TextBox</Type>
            <Mandatory>true</Mandatory>
            <Label>Nom société</Label>
            <Values></Values>
            <DefaultValue></DefaultValue>
          </Control>
          <Control>
            <Id>2</Id>
            <Code>AL_TYPE_SOC</Code>
            <Type>ComboBox</Type>
            <Mandatory>true</Mandatory>
            <Label>Type société<Label>
            <Values>
              <Value Id="COR">Correspondance</Value>
              <Value Id="BAN">Banque</Value>
              <Value Id="FIN">Finance</Value>
              <Value Id="COM">Comptes</Value>
              <Value Id="PRE">Prêt</Value>
            </Values>
            <DefaultValue></DefaultValue>
          </Control>
          <Control>
            <Id>3</Id>
            <Code>SOUS_DOS</Code>
            <Type>TextBox</Type>
            <Mandatory>false</Mandatory>
            <Label>Sous dossier</Label>
            <Values></Values>
            <DefaultValue></DefaultValue>
          </Control>
        </Index>
    </ContentType>
    <ContentType Id="DOCUMENT_FRN" Value="Document RH">
      <SecretsLevels>
        <SecretLevel label="Confidentiel RH">600</SecretLevel>
      </SecretsLevels>
        <Index>
          <Control>
            <Id>1</Id>
            <Code>NOM</Code>
            <Type>TextBox</Type>
            <Mandatory>true</Mandatory>
            <Label>Nom collaborateur</Label>
            <Values></Values>
            <DefaultValue></DefaultValue>
          </Control>
          <Control>
            <Id>2</Id>
            <Code>AL_TYPE_DOC</Code>
            <Type>ComboBox</Type>
            <Mandatory>true</Mandatory>
            <Label>Type document</Label>
            <Values>
              <Value Id="CV">CV</Value>
              <Value Id="FP">Fiche de paie</Value>
              <Value Id="DIV">Divers</Value>
            </Values>
            <DefaultValue></DefaultValue>
          </Control>
        </Index>
      </ContentType>
  </ContentsTypes>
</Controls> 

var query = from device in loaded.Descendants("ContentType")
                select new
                {
                    ContTypeId    = device.Attribute("Id").Value,
                    ContTypeValue = device.Attribute("Value").Value,
                    SecretsLvl = from deviceSecrets in device.Descendants("SecretsLevels")
                                 select new
                                 {
                                     SecretsLevel_Label = deviceSecrets.Attribute("label").Value,
                                     SecretsLevel_Value = deviceSecrets.Attribute("Value").Value,
                                     Index = from deviceIndex in deviceSecrets.Descendants("Index/Control")
                                             let valuesDig = deviceIndex.Element("Values").Elements("Value")
                                             let valuesAtt = deviceIndex.Element("Values").Elements("Value").Attributes("Id")
                                             select new 
                                             {
                                                 AttribDig = from attrDig in valuesAtt select attrDig.Value,
                                                 IdDig     = deviceIndex.Element("Id").Value,
                                                 CodeDig   = deviceIndex.Element("Code").Value,
                                                 TypeDig   = deviceIndex.Element("Type").Value,
                                                 LabelDig  = deviceIndex.Element("Label").Value,
                                                 MandaDig  = deviceIndex.Element("Mandatory").Value,
                                                 DefaultValueDig = deviceIndex.Element("DefaultValue").Value,
                                             }
                                 }
                };