Wordpress: Create relationship between two taxonomy's using ACF

functions::get_connected_terms.php

<?php
$all_tax_a_terms = get_terms( array( 'taxonomy' => 'taxonomy_a', 'hide_empty' => false) );
foreach ($all_tax_a_terms as $a_term) {
  $b_terms_set_to_a_term = get_terms( array(
    'taxonomy' => 'taxonomy_b',
    'meta_key'  => 'acf-key-for-taxonomy-b',
    'meta_value'  => $a_term->slug,
    'hide_empty' => false )
  );
}