title: Odata query filtering first element of a list
body: <p>I have an OData query working fine, returning me something like:</p>
  <pre><code>    [
          {
              &quot;Id&quot;: &quot;ABC&quot;,
              &quot;Related&quot;: {
                  &quot;Id&quot;: &quot;123&quot;
              },
              &quot;Children&quot;: [
                  {
                      &quot;Id&quot;: &quot;1&quot;
                  },
                  {
                      &quot;Id&quot;: &quot;2&quot;
                  }
              ]
          },
          {
              &quot;Id&quot;: &quot;DEF&quot;,
              &quot;Related&quot;: {
                  &quot;Id&quot;: &quot;123&quot;
              },
              &quot;Children&quot;: [
                  {
                      &quot;Id&quot;: &quot;3&quot;
                  },
                  {
                      &quot;Id&quot;: &quot;4&quot;
                  }
              ]
          }
      ]
  </code></pre>
  <p>I want to filter on the first children of every object.
  I have no problem filtering on the value or Related (1-1 relation), but I cannot find a way to filter on the first children (0-N relation).</p>
  <p>To filter on the 1-1 entity, I do the filter with <strong>Related/Id eq '123'</strong>, but I could not find a syntax similar to <strong>Children[0]/Id eq '1'</strong>.</p>
  <p>Any idea?</p>
  <p>Thanks!</p>