My backend return this :

{
    "FirstResponse": [
        {
            "MyField1": "AAA",
            "MyField2": "AAAAAAA"
        },
        {
            "MyField1": "BBB",
            "MyField2": "BBBBBBB"
        },
        {
            "MyField1": "CCC",
            "MyField2": "CCCCC"
        }
    ],
    "SecondResponse": [
        {
            "FirstName": "FirstNameA",
            "LastName": "LastNameA"
        },
        {
            "FirstName": "FirstNameB",
            "LastName": "LastNameB"
        }
    ]   
}

I'd like map FirstReponse to a variable and SecondResponse to another variable.

How can I adapt the code below ?

search(): Observable {
  let apiURL = `......`;
  return this.http.get(apiURL) 
      .map(res => res.json())
}

Update : Excepted result In one variable this :

[
    {
        "MyField1": "AAA",
        "MyField2": "AAAAAAA"
    },  
    {
        "MyField1": "BBB",
        "MyField2": "BBBBBBB"
    },
    {
        "MyField1": "CCC",
        "MyField2": "CCCCC"
    }
]

In a second :

[
    {
        "FirstName": "FirstNameA",
        "LastName": "LastNameA"
    },
    {
        "FirstName": "FirstNameB",
        "LastName": "LastNameB"
    }
]