Finding node order in XML document in SQL Server

Question

How can I find the order of nodes in an XML document?

What I have is a document like this:

Answer 1

I see answer by @Ben and... get new sollution

 row_number() over (order by (select null))

as

  SELECT value.value('@code', 'varchar(20)') code, 
  value.value('../@code', 'varchar(20)') parent, 
  row_number() over (order by (select null))
  FROM @xml.nodes('/root//value') n(value)