If every meta value has the key f_name
$meta = get_post_meta($post->ID, "company_wp_box_g", true);
echo $meta['fname'];
If you’re not sure of the contents & want to search for the first one available
$name = false;
$meta = get_post_meta($post->ID, "company_wp_box_g", false);
foreach($meta as $array) {
if(isset($array['f_name'])) {
$name = $array['f_name'];
break;
}
}
echo $name;