title: Primeng p-multiSelect search function is not working
body: <p>I'm working with PrimeNg to filter columns on my p-table.</p>
  <p>I have <code>p-multiSelect</code> nested inside a <code>p-ColumnFilter</code>.</p>
  <p>The filtering is working as expected, however the search function inside the <code>p-multiSelect</code> is always returning <code>no results found</code>.</p>
  <p>Here is my template code:</p>
  <pre class="lang-xml prettyprint-override"><code>&lt;th class=&quot;table-header-primary&quot; [ngStyle]=&quot;{'width':'200px'}&quot; [pSortableColumn]=&quot;'docCategory'&quot;&gt;Type
    &lt;p-columnFilter  class=&quot;p-ml-auto&quot; type=&quot;text&quot; field=&quot;doctypeLabel&quot;  matchMode=&quot;in&quot; display=&quot;menu&quot;  [showApplyButton]=&quot;false&quot; [showMatchModes]=&quot;false&quot; [showOperator]=&quot;false&quot; [showAddButton]=&quot;false&quot;&gt;
      &lt;ng-template pTemplate=&quot;filter&quot; let-value let-filter=&quot;filterCallback&quot;&gt;
        &lt;p-multiSelect  [(ngModel)]=&quot;doctypeLabel&quot; [options]=&quot;_doctypeLabelList&quot;  placeholder=&quot;Select&quot; (onChange)=&quot;filter($event.value)&quot;&gt;
        &lt;/p-multiSelect&gt;
        &lt;/ng-template&gt;
    &lt;/p-columnFilter&gt;&lt;/th&gt;
  </code></pre>
  <p>Here is my relevant typescript file:</p>
  <pre class="lang-js prettyprint-override"><code>_doctypeLabelList:any[]=[];
  doctypeLabel:any=&quot;&quot;;
    constructor() {
    }
  </code></pre>
  <p>I've attached two photos that I hope make my issue clear.</p>
  <p>My multiselect dropdown, populated with appropriate fields from <code>_doctypeLabelList</code>:</p>
  <p><img src="https://i.stack.imgur.com/HpeIA.png" alt="1" /></p>
  <p>Once I try to search for matching values in dropdown:</p>
  <p><img src="https://i.stack.imgur.com/5Nfj2.png" alt="2" /></p>
  <p>I have tried to one way bind <code>doctypeLabel</code> but that did not work. The <code>_doctypeLabelList</code> is showing fine in the options dropdown, it's just when searching in the input bar always results in immediate <code>no results found</code>. I'm really at a lost of what else to try. I've looked at the PrimeNg documentation over and over and didn't find any results. The example in the documentation was a rather simple use case, so I'm wondering if somehow the <code>p-columnFilter</code> is affecting my <code>p-multiSelect</code>.</p>