title: Is it possible to fill in SearchInput with data from current endpoint?
body: <p>React-admin documentation suggests to filter data via referencing to another endpoint like:</p>
  <pre><code>    &lt;Filter {...props}&gt;
          &lt;TextInput label=&quot;Search&quot; source=&quot;q&quot; alwaysOn /&gt;
          &lt;ReferenceInput
              label=&quot;User&quot;
              source=&quot;userId&quot;
              reference=&quot;users&quot;
              allowEmpty
          &gt;
              &lt;SelectInput optionText=&quot;name&quot; /&gt;
          &lt;/ReferenceInput&gt;
      &lt;/Filter&gt;
  </code></pre>
  <p>But in my case there is no need to refer to another endpoint and I would like to filter current list relying on data from this list:</p>
  <pre><code>  &lt;Filter {...props}&gt;
      &lt;SelectInput label='Title' source='Title' allowEmpty/&gt;
    &lt;/Filter&gt;
  </code></pre>
  <p>But the filter list is empty. How can I data from &quot;title&quot;? I will be grateful for any possible help.</p>