gistfile1.txt

                renderObj = COA
                renderObj {
                        wrap = <ul>|</ul>
                        1 = TEXT
                        1 {
                                wrap = <li>|</li>
                                typolink {
                                        parameter.field = link
                                }
                                field = title
                        }
                }

gistfile2.txt

Using

$this->cObj->cObjGetSingle($this->conf[$endpoint . '.']['renderObj'], $this->conf[$endpoint . '.']['renderObj.']);

outputs

<ul>
  <li>
    <a href="..." >Element 1</a>
  </li>
</ul>
<ul>
  <li>
    <a href="..." >Element 2</a>
  </li>
</ul>

would like

<ul>
  <li>
    <a href="..." >Element 1</a>
  </li>
  <li>
    <a href="..." >Element 2</a>
  </li>
</ul>

the wrap should no be inside renderObj. I can't suggest a solution because I don't really get the context by the code you provided. Either way the ul wrap has to be "one level above".

I will be creating a <ul><li></li></ul> list with data from a external service (Disqus)

            $response = json_decode($disqusService->request());
            foreach ($response->response as $response) {
                    $this->cObj->data = get_object_vars($response);
                    $content .= $this->cObj->cObjGetSingle($this->conf[$endpoint . '.']['renderObj'], $this->conf[$endpoint . '.']['renderObj.']);
            }

If i move the wrap part on level up, example:

[endpoint name] {
  render {
    wrap = <ul>|<ul>
    renderObj {
      [like above]
    }
  }
}

How do I code-wise apply the <ul> (wrap) correctly

I'd do it this way:
$content .= $this->cObj->wrap($this->cObj->cObjGetSingle($this->conf[$endpoint . '.']['renderObj'], $this->conf[$endpoint . '.']['renderObj.']), '

|

');

Something like:

[endpoint name] {
  stdWrap.wrap = <ul>|<ul>
  renderObj {
    [like above]
  }
}

$response = json_decode($disqusService->request());
$listcontent = '';
foreach ($response->response as $response) {
   $this->cObj->data = get_object_vars($response);
   $listcontent .= $this->cObj->cObjGetSingle($this->conf[$endpoint . '.']['renderObj'], $this->conf[$endpoint . '.']['renderObj.']);
}
$listcontent = $this->cObj->stdWrap($listcontent, $this->conf[$endpoint . '.']['stdWrap.']);
$content .= $listcontent;