jq

{
  "foo": {
    "bar": [
    {
      "key": "1-key",
        "value": "1-value"
    },
    {
      "key": "2-key",
      "value": "2-value",
      "option": "2-opt"
    }
    ],
    "baz": [
    {
      "key": "3-key",
      "value": "3-value",
      "option": "3-opt"
    },
    {
      "key": "4-key",
      "value": "4-value"
    }
    ]
  }
}

$ cat example.json | jq '.foo.bar'
[
  {
    "key": "1-key",
    "value": "1-value"
  },
  {
    "key": "2-key",
    "value": "2-value",
    "option": "2-opt"
  }
]

$ cat example.json | jq '.foo.bar[]'
{
  "key": "1-key",
  "value": "1-value"
}
{
  "key": "2-key",
  "value": "2-value",
  "option": "2-opt"
}

$ cat example.json | jq '.foo.bar[1]'
{
  "key": "2-key",
  "value": "2-value",
  "option": "2-opt"
}