How to populate select field from View result like in
I don't have time to provide an exact answer, but something along these lines. 

// Programmatically execute view
$view = views_get_view('sel_selistes'); //  view machine name
$view-&gt;set_display("entity_reference_1"); // view display name
// $view-&gt;set_arguments($arg) // looks like you don't have arguments.
$view-&gt;execute();

$view_results = []; // create array
// loop through results
foreach ($view-&gt;result as $row_id =&gt; $row) {
  // some php magic so you add to array like this $view_results[$nid_value] = $some_field_row_value;
}

$form['my_select_field'] = array(
  '#type' =&gt; 'select',
  '#options' =&gt; $view_results,
  '#title' =&gt; $this
    -&gt;t('whatever'),
);