[
  {
   "name": "Product Line 1",
   "reference": "product 1.A identifier"
  },
  {
   "name": "Product Line 1",
   "reference": "product 1.B identifier"
  },
  {
   "name": "Product Line 2",
   "reference": "product 2.A identifier"
  },
  {
   "name": "Product Line 2",
   "reference": "product 2.B identifier"
  }
];

{
 "name": "Master Product Catalog",
 "children": [
             {
              "name": "Product Line 1",
              "children": [
                           { "name": "product 1.A identifier" },
                           { "name": "product 1.B identifier" }
                          ]
             },
             { "name": "Product Line 2",
               "children": [
                            { "name": "product 2.A identifier" },
                            { "name": "product 2.B identifier" }
                           ]
             }
             ]
}

var stratdata = d3.stratify()
                  .id(function(d) { return d.name; })
                  .parentId(function(d) { return d.name; })
                  (mongodb_data);