Yes KnockOut supports recursive templates so you can reference and render the same template inside the template.
An example html in your case would look like this:
<script id="formElementNodeTemplate" type="text/html">
<ul>
<li>Parent <span data-bind="text: text"></span>
<span data-bind="text: value"></span>
<br/>
Children:
<!-- ko template: { name: 'formElementNodeTemplate',
foreach: children } -->
<!-- /ko -->
</li>
</ul>
</script>
<div data-bind="template: { name: 'formElementNodeTemplate', data: $data }">
</div>
Demo JSFiddle.