Document Generation Tagger - nested JSON

Using the Document Generation Add-in for Word, is there a way to access the nested data in JSON without using Tables/Lists feature? Only first 2 fields at level 1 in this sample get 'tagged' for use.

{
  "collection": {
    "level_1_field_1": "level_1_field_1",
    "level_1_field_2": "level_1_field_2",
    "level_1_field_3": [
      {
        "level_2_field_1": "level_2_field_1",
        "level_2_field_2": {
          "level_3_field_1": "level_3_field_1",
          "level_3_field_2": "level_3_field_2",
          "level_3_field_3": "level_3_field_3"
        },
        "level_2_field_3": [
          {
            "level_3_field_4": "level_3_field_4",
            "level_3_field_5": "level_3_field_5"
          }
        ]
      }
    ],
    "links": []
  }
}