Since you did not give the algorithm or example code for conversion, its hard to know exactly what you want. I'll take a guess.

What you have is an adjacency list representation of a graph, and it looks like you want to find all the connected components of that graph and put them into a list. If that is so, then the second example is ok, since you can get to all the nodes by following the links from 'lineitem'.

If you see a problem with the second example, perhaps you are looking for the strongly connected components of a graph, with each element of a component connected to every other component of the graph.

The easiest way to approach this is to use the perl module Graph:

use Graph::Directed;
$G = new Graph::Directed;

   # ... add vertices, edges

@S = $G->strongly_connected_components;
 
# Returns the strongly connected components @S of the 
# graph $G as a list of anonymous lists of vertices, 
# each anonymous list containing the vertices 
#belonging to one strongly connected component.
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