Parse CSV in JSON object

Hi,

I have a JSON data source that looks something like this

{
    "company": {
        "companyId": 1,
        "name": "AdventureWorks",
        "description": ""
    },
    "hierarchies": [
        {
            "depths": [
                {
                    "depth": 0,
                    "name": null
                },
                {
                    "depth": 1,
                    "name": "Company"
                }
            ],
            "allKeys": "1|-1|10"
        }
    ],
    "slicer": null,
    "userToGroup": "Username,GroupId\nJohn,G1\nSarah,G1\nPeter,G1\nKate,G1",
    "groupToKey": "GroupId,Key\nG1,10\nG1,101\nG1,102\nG1,103\nG1,104"
}

And I am only really interested in the last two objects, userToGroup and groupToKey, which both are in a CSV format. Is it possible to use something like xPath to navigate to these two objects and then parse them as CSVs? 

I have an RSD file that gives me userToGroup:

<api:script xmlns:api="http://apiscript.com/ns?v1" xmlns:xs="http://www.w3.org/2001/XMLSchema">

  <!-- See Column Definitions to specify column behavior and use XPaths to extract column values from JSON. -->
  <api:info title="hierarchies" desc="Generated schema file." xmlns:other="http://apiscript.com/ns?v1">
    <!-- You can modify the name, type, and column size here. -->
	"userToGroup"
    <attr name="json.userToGroup"                xs:type="string"  readonly="false"              other:xPath="/json/userToGroup"                 />
  </api:info>

  <api:set attr="DataModel" value="DOCUMENT" />
  <api:set attr="URI" value="http://api.com/api/1" />

  <api:set attr="JSONPath" value="$.hierarchies" />

But everything ends up in a single column/row. 

Does anyone have any experience working with this sort of JSON/CSV format combination?