Query Custom post type with Taxonomy Custom Field

Question

I have a Taxonomy called Cities. I have created a custom field for this taxonomy, using ACF, called Country So I can create a City and select the Country (select list with predefined options) it belongs to in the dashboard.

I then create my Post, and select a City it belongs to. (ie Paris)

On front end, I have created a drop down list from the value of the ACF custom field which works fine, like this

  $field_key = "field_1234564545445";
  $field = get_field_object($field_key);

  if( $field )
  {
          echo '<select name="country">';
          echo '<option value="">Choose Country</option>';
          foreach( $field['choices'] as $k => $v )
          {
              echo '<option value="' . $k . '">' . $v . '</option>';
          }
      echo '</select>';
  }

This gives me a list of the Country used by the Taxonomy Cities. So I get a list like France, Italy, Spain etc. No I am trying to query my post type using one of these country, but I can't manage to get a result.

$args = array( 
    'posts_per_page'    => '12',
    'post_type' => 'ARTICLES',
    'orderby' => 'date',
    'order' => ASC,
    'meta_query' => array(
          array(
           'key'      => 'country',//Also tried field_1234564545445
           'compare'  => '=',
           'value'    => $country,
        ),    
      ),
      'paged' => $paged,
    );

Will appreciate a pointer thx

Answer 1

Ok, I did it another way.

First, get all the terms for the taxonomy. If the term is equal to the value requested, put it into an array Then do the tax_query with this array.

Final

$argsc = array(
'order'             => 'ASC',
'hide_empty'        => true,
'fields'            => 'all', 
); 

$termsc = get_terms("cities", $argsc);
$cities_array = array( );
foreach ( $termsc as $cterm ) {
//Get country Customf ield for that term
$thecountry = get_field( 'country', $cterm );
 if($country == $thecountry){
 //if custom field == variable from select/search put in array
  array_push($cities_array,$cterm->name);
 }else{
 //do nothing
 }
}

ksort( $cities_array);//just sorting
$args = array(
    // Arguments for your query.
    'posts_per_page'    => '12',
    'post_type' => 'ARTICLES',
        'orderby' => 'date',
        'order' => ASC,
        'tax_query' => array(
                array(
                'taxonomy' => 'cities',
                'field'    => 'slug',
                'terms'    => $cities_array,
            ),

        ),
      'paged' => $paged,
    );