Thank you, that helped.
So, I found the error in the code, and I corrected it, you will find the working version below. I also made an adjustment to the filter, like so: https://i.imgur.com/N2U0AYz.png
Since those are numeri values, and there is a possibility of multiple values, I changed the inner logic to ‘OR’ as you see.
With this combination, it should merge the town names, and show the results matching those meta values.
add_filter('asp_pre_get_front_filters', 'asp_locations_pre_get_front_filters', 10, 2);
function asp_locations_pre_get_front_filters($filters, $type) {
if ( $type == 'custom_field' ) {
foreach ($filters as $k => $filter) {
if ( $filter->data['field'] == '_location_id' && class_exists('EM_Locations') ) {
$location_ids = array();
foreach ( $filter->get() as $kk=>$item ) {
if ( is_numeric($item->value) ) {
$location_ids[] = $item->value;
}
}
$filter->remove();
$locations = EM_Locations::get( array('location'=>array_unique($location_ids)) );
$locarr = array();
if ( is_array($locations) && count($locations) > 0 ) {
foreach ( $locations as $loc ) {
if ( isset($locarr[$loc->location_town]) ) {
$locarr[$loc->location_town] .= '::' . $loc->location_id;
} else {
$locarr[$loc->location_town] = $loc->location_id;
}
}
ksort($locarr);
foreach ( $locarr as $key => $loc ) {
if ( !empty($key) && !empty($loc) )
$filter->add(array(
'value' => $loc,
'label' => $key,
));
}
}
$filters[$k] = $filter;
}
}
}
return $filters;
}