Получаем опции и тв и работает над выводом.

get_array_megre.php

<?php
$tv_prod_coffee_ids = (explode(',' , $modx->resource->getTVValue('prod_coffee_ids')));
$tv_prod_coffee_sprecial = (explode(',' , $modx->resource->getTVValue('prod_coffee_sprecial')));
$option_coffee_total = explode(',' , $modx->getOption('coffee_total'));

$output = $tv_prod_coffee_sprecial 
  ? $tv_prod_coffee_sprecial
  : array_filter(array_unique(array_merge($tv_prod_coffee_ids,$option_coffee_total)));
  
return (implode(',' , $output));