I have this following json nested structure that i need to construct in pentaho:

{
  "num_matricula": "4242424",
  "limit_date": "2018-01-01",
  "admission_date": "2018-01-01",
  "cost_center": "anywhere",
  "pos_number": "pos-test",
  "role": "b63e065f-d7e0-49e1-91b7-88f74516e3fe",
  "department": "bf559996-a8b9-4f5e-af57-86111b0dbde3",
  "pagamento": {
    "vinculo": "clt",
    "valor": "4200",
    "recorrencia": "mensalista",
    "contaBancaria": {
      "banco": "001",
      "carta": "c9160763-db6c-4e8c-a1ad-ad8709c99be2"
    }
  },
  "deficiencia": false,
  "jornada": "De segunda a sexta das 15 as 19",
  "profile": {
    "name": "John Doe",
    "email": "john.doe@acessodigital.com.br",
    "mobile": "11911111111"
  },
  "exame": {
    "clinica": "6dc84ce4-7d9f-48ec-b9b1-a8a895a21fd4",
    "data": "2018-01-01",
    "hora": "14:00",
    "obs": "Comparecer de manhã",
    "guia": "e37dab24-c7a4-4b92-b9d1-32ed538b8300",
  },
  "docs": ["c9e26093-5e0c-4bd2-bea3-ac5182a6179f"],
  "send_sms": true,
  "send_email": true
}

All the values come from the step "Select Values" which one gather the columns and the values to construct the json structure how it is showed in the following screenshot:

I've seen some solutions about using JavaScript to construct nested json structure in Pentaho, but i was not so sure about to create this using values from other steps. Can someone help me to construct this in pentaho? Pleasee.