Hi Jonathan,
I believe the code you provided above is the code to be put in archives.php right? I can’t get it to work unless the “View all” link from the company-single.php works, which doesnt:
<?php
$company_ID = $post->ID; //get the id of the current company
$archive = get_post_type_archive_link('post').'?company='.$company_ID;
?>