WooCommerce Child Categories on Parent Category Archive Page

Child Categories on Parent Archive.php

// Hook into the WooCommerce before shop loop to display subcategories
add_action('woocommerce_before_shop_loop', 'display_woo_subcategories', 15);
function display_woo_subcategories() {
    if (!is_product_category()) {
        return;
    }

    $term_id = get_queried_object_id();
    $taxonomy_name = 'product_cat';
    $termchildren = get_term_children($term_id, $taxonomy_name);

    if (empty($termchildren)) {
        return;
    }

    echo '<div class="woo-subcategories multi-column">';
    echo '<ul>';

    foreach ($termchildren as $child) {
        $term = get_term_by('id', $child, $taxonomy_name);
        $thumbnail_id = get_term_meta($term->term_id, 'thumbnail_id', true);
        $image = wp_get_attachment_url($thumbnail_id);

        echo '<li>';
        echo '<a href="' . esc_url(get_term_link($term, $taxonomy_name)) . '">';
        if ($image) {
            echo '<img src="' . esc_url($image) . '" alt="' . esc_attr($term->name) . '" />';
        }
        echo '<h3>' . esc_html($term->name) . '</h3>';
        echo '</a>';
        echo '</li>';
    }

    echo '</ul>';
    echo '</div>';
}

style.css

.woo-subcategories.multi-column ul {
    display: flex;
    flex-wrap: wrap;
    list-style: none;
    padding: 0;
    margin: 0;
}

.woo-subcategories.multi-column ul li {
    flex: 1 1 30%;
    box-sizing: border-box;
    text-align: center;
}

.woo-subcategories.multi-column ul li img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto 10px;
}

.woo-subcategories.multi-column ul li h3 {
    margin: 0;
    font-size: 16px;
    line-height: 1.5;
}