title: jmespath flatten multiple hash values
body: <p>Ideally, I want to write a query that returns a flat list output: <code>["abc", "bcd", "cde", "def"]</code> from the following JSON sample:</p>
  
  <pre><code>{
    "l_l": [
      [1,2,3],
      [4,5,6]
    ],
    "l_h_l": [
      { "n": [10,2,3] },
      { "n": [4,5,60] }
    ],
    "l_h_m": [
      {
        "n": {
          "1234": "abc",
          "2345": "bcd"
        }
      }, {
        "n": {
          "3456": "cde",
          "4567": "def"
        }
      }
    ]
  }
  </code></pre>
  
  <p>The closest I can get is <code>l_h_m[].n.*</code> which returns the contents that I want as an unflattened list of lists:</p>
  
  <pre><code>[
    [
      "abc",
      "bcd"
    ],
    [
      "cde",
      "def"
    ]
  ]
  </code></pre>
  
  <p>jmespath lets you flatten lists of lists. Queries <code>l_l[]</code> and <code>l_h_l[].n[]</code> both returned flattened results, when the source json is structured that way.</p>