Displaying child taxonomy before parent

by

My assumption here is that within your data structure you have only two level hierarchy:

  1. Countries are always top level parent terms (they never have their own parents),
  2. Streets are first level children, and each street only has one parent and no children.

Do you need a list of all terms? In that case you could output all Streets by picking terms that do not have children, then loop through them to show their parents:

    <?php
    $terms = get_terms( [
       'taxonomy'   => 'your-taxonomy-name',
       'hide_empty' => false,
       'childless'  => true, // this will make sure we pick only terms that have no children, so no countries, only streets
    ] );
    ?> 

    <ul>
        <?php
        foreach( $terms as $street ) {
            $country = get_term( $street->parent, 'your-taxonomy-name' );

            if ( ! is_wp_error( $country ) ) {
                echo sprintf( '<li>%1$s, %2$s</li>', $street->name, $country->name );
            }
        }
        ?>
    <ul>