hook_views_pre_render - how to print field x after each loop

Question

I have a grouped view that displaces content containing multiple entity references. I have a field that generates multiple times, because of those entity references. I've looked into modifying views-view-group.html.twig with no luck. Now I'm trying to figure out how to use hook_views_pre_render to accomplish this.

(If it comes up... no, using 'Views Field View' didn't work)

I currently have results like this:

Group Title
 - Item one
   -- entity-ref1
   -- Field-x
   -- entity-ref2
   -- Field-x

I want this:

Group Title 
 - Item one 
  -- entity-ref-item1
  -- entity-ref-item2
  -- Field x

I've already got the hook set up in a module. I'm just trying to figure out how to use it to rearrange fields and output Field x - After the rest of each entry has output. I haven't found anything.

UPDATE: I tried this solution for removing duplicates - BUT.. it's removing the multiple entity references along with the multiple Field X. I just one Field X pared down to one:

    function webinar_rearrange_views_pre_render(\Drupal\views\ViewExecutable $view) { 
      if ($view->id() == 'webinars') {
        $filtered_nids = array();

        foreach ($view->result as $key => $row) {
          if (in_array($row->nid, $filtered_nids)) {
            unset($view->result[$key]); // remove the duplicate
          } else {
            $filtered_nids[] = $row->nid;
          }
        }
      } 
    }

Answer 1

This isn't the answer I was looking for, but it solves the issue until a better method is found.

Basically, the problem is that a specific field - a custom text 'find out more' field was showing three times (for example) when a row had three authors (entity ref. fields)

Since the 'find out more' field was the last item in each row, I overrode the "views-view-unformatted" twig template and, inside of the 'for' loop I added an extra bit, to change the class of the last item. Then, with CSS, I could hide the fields with 'views-row' class, and display 'views-row-last'

Here's what I added to that twig file:

    {% if loop.last %}
        {%
        set row_classes = [
          default_row_class ? 'views-row-last',
        ]
       %}

    {% endif %}