How to create template for children category?

I have found answer, based on this post

For cases when someone wants to have different template for child category. For example, if you have categories ordered like this: continent->country->city. And for example, you need a different template for city. First, we look if city have a children, if not, we call city template, the last child.
In else statement we look if current category has a parent and based on that we display country template. And continent category template will be untouched, it will have category template.

// Different template for subcategories
function wpd_subcategory_template( $template ) {
    $cat        = get_queried_object();
    $children   = get_terms( $cat->taxonomy, array(
        'parent'     => $cat->term_id,
        'hide_empty' => false
    ) );

    if(!$children) {
        $template = locate_template('category-country-city.php');
    } elseif( 0 < $cat->category_parent ) {
        $template = locate_template('category-country.php');
    }

    return $template;
}