In wordpress, Im trying to loop through every year archives, displaying a list of every mouth per year.

The html output should look like this:

//year output
<ul>
 <li>
  2020
  //month output
  <ul>
    <li>month1</li>
    <li>month2</li>
    <li>month3</li>
  </ul>
 </li>
 <li>
   2019
   <ul>
     <li>month1</li>
     <li>month2</li>
     <li>month3</li>
   </ul>
  </li>
</ul>

But the problem is, its repeating all months of every year for each year.

Here is the problem php, I dont know how to write the loop correctly:

<?php
    foreach($months as $month) : $year_current = $month->year;
?>
    <li class='list-group-item month'>
        <a href="<?php bloginfo('url') ?>/<?php echo $month->year; ?>/<?php echo date("m", mktime(0, 0, 0, $month->month, 1, $month->year)) ?>/?post_type=<?php echo $current_post_type ?>">
        <span class="archive-month"><?php echo date_i18n("F", mktime(0, 0, 0, $month->month, 1, $month->year)) ?></span>
        </a>
    </li>
<?php endforeach;?>

Here is the full php:

<aside class="cms-sidebar">
                        <h3 class="cms-sidebar-ttl js-toggle-menu-01">過去の記事</h3>
                      <div class="side-element">
                            <ul class="side-list">
                                <!-- year -->
                                <?php
                                    global $wpdb;
                                    $limit = 0;
                                $year_prev = null;
                                $current_post_type = get_post_type();
                                $months = $wpdb->get_results("SELECT DISTINCT MONTH( post_date ) AS month , YEAR( post_date ) AS year, COUNT( id ) as post_count FROM $wpdb->posts WHERE post_status = 'publish' and post_date <= now( ) and post_type = '$current_post_type' GROUP BY month , year ORDER BY post_date DESC");

                                foreach($months as $month) : $year_current = $month->year;
                                    if ($year_current != $year_prev){
                              ?>
                                <li class="side-item">
                                    <h3 class="side-sub-element-ttl js-toggle-menu-02">
                                        <?php
                                                $args = array(
                                                        'post_type' => $current_post_type,
                                                        'date_query' => array(
                                                                'year'  => $month->year

                                                        )
                                                );
                                                $year_query = new WP_Query($args);
                                        ?>
                                        <?php echo $month->year; ?>年
                                    </h3>
                                    <div class="js-toggle-content">
                                        <!-- months -->
                                        <ul class="side-sub-list flex-row">

                                            <?php
    foreach($months as $month) : $year_current = $month->year;
?>
    <li class='list-group-item month'>
        <a href="<?php bloginfo('url') ?>/<?php echo $month->year; ?>/<?php echo date("m", mktime(0, 0, 0, $month->month, 1, $month->year)) ?>/?post_type=<?php echo $current_post_type ?>">
        <span class="archive-month"><?php echo date_i18n("F", mktime(0, 0, 0, $month->month, 1, $month->year)) ?></span>
        </a>
    </li>
<?php endforeach;?>

                                    </ul>
                                        <!-- end of months -->
                                    </div>
                                </li>
                            <?php } ?>
                            <?php
                            $year_prev = $year_current;
                            endforeach;
                            ?>
                            <!-- end of year -->

                            </ul>
                      </div>
                    </aside>