"On Sale" Filter in the Admin Products List

add_action( 'restrict_manage_posts', function ( $post_type ) {
    if ( 'product' !== $post_type ) {
        return;
    }

    $current = isset( $_GET['wpide_on_sale'] ) ? sanitize_key( wp_unslash( $_GET['wpide_on_sale'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification

    echo '<label for="wpide-on-sale" class="screen-reader-text">' . esc_html( 'Filter by sale' ) . '</label>';
    printf(
        '<select name="wpide_on_sale" id="wpide-on-sale"><option value="">%1$s</option><option value="yes" %2$s>%3$s</option><option value="no" %4$s>%5$s</option></select>',
        esc_html( 'Sale status' ),
        selected( $current, 'yes', false ),
        esc_html( 'On sale' ),
        selected( $current, 'no', false ),
        esc_html( 'Not on sale' )
    );
} );

add_action( 'pre_get_posts', function ( $query ) {
    if ( ! is_admin() || ! $query->is_main_query() || 'product' !== $query->get( 'post_type' ) || empty( $_GET['wpide_on_sale'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification
        return;
    }

    $ids = wc_get_product_ids_on_sale();
    $ids = array_values( array_unique( array_filter( array_map( 'wp_get_post_parent_id', $ids ) ) + $ids ) );

    if ( 'yes' === $_GET['wpide_on_sale'] ) { // phpcs:ignore WordPress.Security.NonceVerification
        $query->set( 'post__in', $ids ? $ids : array( 0 ) );
    } else {
        $query->set( 'post__not_in', $ids );
    }
} );