title: Filter on nested array with jmespath (using az cli)
body: <p>I would like to know if a value in a TXT record is already available in the DNS:</p>
  
  <pre><code>az network dns record-set txt show -g myresourcegroup -z 'mydomain' -n 'mytxtvalues'
  </code></pre>
  
  <p>This is the part of the json result where it's all about:</p>
  
  <pre><code> "txtRecords": [
      {
        "value": [
          "abc"
        ]
      },
      {
        "value": [
          "def"
        ]
      }
    ]
  </code></pre>
  
  <p>I tried many queries. These are 2 which I expected to work.</p>
  
  <pre><code>az network dns record-set txt show -g myresourcegroup -z 'mydomain.com' -n 'mytxtvalues' --query txtRecords[?value[?starts_with(@, 'abc')]]
  
  az network dns record-set txt show -g myresourcegroup -z 'mydomain.com' -n 'mytxtvalues' --query txtRecords[*].value[?starts_with(@, 'abc')]]
  </code></pre>
  
  <p>The result is:</p>
  
  <blockquote>
    <p><em>At line:1 char:123
    + ...  'mytxtvalues' --query txtRecords[?value[?starts_with(@, 'abc') ...
    +                                                                 ~ Unrecognized token in source text. At line:1 char:124
    + ... 'mytxtvalues' --query txtRecords[?value[?starts_with(@, 'abc')] ...
    +                                                                 ~ Missing argument in parameter list.</em></p>
  </blockquote>
  
  <p>It looks like the @ used to filter the array is not recognized. But I don't know how to query otherwise.</p>
  
  <p>What would be a correct query to know if value abc is already in the list?</p>