Preciso transformar arquivos XML grandes que tenham uma estrutura aninhada (hierárquica) do formulário

<Root>
   Flat XML
   Hierarchical XML (multiple blocks, some repetitive)
   Flat XML
</Root>

em um formato mais plano ("desfiado"), com 1 bloco para cada bloco aninhado repetitiv

Os dados têm inúmeras tags diferentes e variações de hierarquia (especialmente no número de tags do XML fragmentado antes e depois do XML hierárquico); portanto, idealmente, nenhuma suposição deve ser feita sobre nomes de tags e atributos ou o nível hierárquic

Uma visualização de nível superior da hierarquia para apenas quatro níveis seria algo como

<Level 1>
   ...
   <Level 2>
      ...
      <Level 3>
        ...
        <Level 4>A</Level 4>
        <Level 4>B</Level 4>
        ...
      </Level 3>
      ...
   </Level 2>
   ...
</Level 1>

e a saída desejada seria

<Level 1>
  ...
  <Level 2>
    ...
      <Level 3>
        ...
        <Level 4>A</Level 4>
        ...
      </Level 3>
    ...
  </Level 2>
  ...
</Level 1>

<Level 1>
  ...
  <Level 2>
    ...
      <Level 3>
        ...
        <Level 4>B</Level 4>
        ...
      </Level 3>
    ...
  </Level 2>
  ...
</Level 1>

Ou seja, se em cada níveli temLi componentes diferentes, um total deProduct(Li) componentes diferentes serão produzidos (apenas 2 acima, pois o único fator de diferenciação é o Nível 4, entãoL1*L2*L3*L4 = 2).

Pelo que vi ao redor, o XSLT pode ser o caminho a seguir, mas qualquer outra solução (por exemplo, StAX ou mesmo JDOM) serviria.

Um exemplo mais detalhado, usando informações fictícias, seria

<Employee name="A Name">
  <Address>123 A Street</Address>
  <Age>28</Age>
  <EmploymentHistory>
    <Employment country="US">
      <Comment>List of previous jobs in the US</Comment>
      <Jobs>3</Jobs>
      <JobDetails>
        <Job title = "Senior Developer">
          <StartDate>01/10/2001</StartDate>
          <Months>38</Months>
        </Job>
        <Job title = "Senior Developer">
          <StartDate>01/12/2004</StartDate>
          <Months>6</Months>
        </Job>
        <Job title = "Senior Developer">
          <StartDate>01/06/2005</StartDate>
          <Months>10</Months>
        </Job>
      </JobDetails>
    </Employment>
  </EmploymentHistory>
  <EmploymentHistory>
    <Employment country="UK">
      <Comment>List of previous jobs in the UK</Comment>
      <Jobs>2</Jobs>
      <JobDetails>
        <Job title = "Junior Developer">
          <StartDate>01/05/1999</StartDate>
          <Months>25</Months>
        </Job>
        <Job title = "Junior Developer">
          <StartDate>01/07/2001</StartDate>
          <Months>3</Months>
        </Job>
      </JobDetails>
    </Employment>
  </EmploymentHistory>
  <Available>true</Available>
  <Experience unit="years">6</Experience>
</Employee>

Os dados acima devem ser fragmentados em 5 blocos (ou seja, um para cada<Job> block), cada um dos quais deixará todas as outras tags idênticas e terá apenas um<Job> elemento. Então, considerando os 5 diferentes<Job> blocos no exemplo acima, o XML transformado ("desfiado") seria

<Employee name="A Name">
  <Address>123 A Street</Address>
  <Age>28</Age>
  <EmploymentHistory>
    <Employment country="US">
      <Comment>List of previous jobs in the US</Comment>
      <Jobs>3</Jobs>
      <JobDetails>
        <Job title = "Senior Developer">
          <StartDate>01/10/2001</StartDate>
          <Months>38</Months>
        </Job>
      </JobDetails>
      <Available>true</Available>
     <Experience unit="years">6</Experience>
    </Employment>
  </EmploymentHistory>
</Employee>

<Employee name="A Name">
  <Address>123 A Street</Address>
  <Age>28</Age>
  <EmploymentHistory>
    <Employment country="US">
      <Comment>List of previous jobs in the US</Comment>
      <Jobs>3</Jobs>
      <JobDetails>
        <Job title = "Senior Developer">
          <StartDate>01/12/2004</StartDate>
          <Months>6</Months>
        </Job>
      </JobDetails>
      <Available>true</Available>
     <Experience unit="years">6</Experience>
    </Employment>
  </EmploymentHistory>
</Employee>

<Employee name="A Name">
  <Address>123 A Street</Address>
  <Age>28</Age>
  <EmploymentHistory>
    <Employment country="US">
      <Comment>List of previous jobs in the US</Comment>
      <Jobs>3</Jobs>
      <JobDetails>
        <Job title = "Senior Developer">
          <StartDate>01/06/2005</StartDate>
          <Months>10</Months>
        </Job>
      </JobDetails>
      <Available>true</Available>
     <Experience unit="years">6</Experience>
    </Employment>
  </EmploymentHistory>
</Employee>

<Employee name="A Name">
  <Address>123 A Street</Address>
  <Age>28</Age>
  <EmploymentHistory>
    <Employment country="UK">
      <Comment>List of previous jobs in the UK</Comment>
      <Jobs>3</Jobs>
      <JobDetails>
        <Job title = "Junior Developer">
          <StartDate>01/05/1999</StartDate>
          <Months>25</Months>
        </Job>
      </JobDetails>
      <Available>true</Available>
     <Experience unit="years">6</Experience>
    </Employment>
  </EmploymentHistory>
</Employee>

<Employee name="A Name">
  <Address>123 A Street</Address>
  <Age>28</Age>
  <EmploymentHistory>
    <Employment country="UK">
      <Comment>List of previous jobs in the UK</Comment>
      <Jobs>3</Jobs>
      <JobDetails>
        <Job title = "Junior Developer">
          <StartDate>01/07/2001</StartDate>
          <Months>3</Months>
        </Job>
      </JobDetails>
      <Available>true</Available>
     <Experience unit="years">6</Experience>
    </Employment>
  </EmploymentHistory>
</Employee>