未经测试，但我认为这会成功！

<?php

// Get date Categories
$date_cats = get_categories(array(
    \'include\' => \'1,2,3,4\'
));

// Loop through date categories
foreach($date_cats as $date_cat) :

    // Get link of current date category
    $date_cat_link = get_category_link( $date_cat->cat_ID ); ?>

    <ul>
        <li><a href="<?php echo $date_cat_link; ?>"><?php echo $date_cat->name; ?></a>
            <ul>
            <?php
            // Get ID of current date category
            $date_cat_id = $date_cat->cat_ID;

            // Get ABC categories
            $abc_cats = get_categories(array(
                \'include\' => \'5,6,7\'
            ));

            // Loop through ABC catagories
            foreach($abc_cats as $abc_cat) :

                // Get ID of current ABC category
                $abc_cat_id = $abc_cat->cat_ID;
                // Get link of current ABC category
                $abc_cat_link = get_category_link( $abc_cat->cat_ID );

                // Run a query for posts that are in this date category AND this ABC category
                $query = new WP_Query( array(
                    \'posts_per_page\' => -1,
                    \'category__and\' => array( $date_cat_id, $abc_cat_id )
                ));

                // If there are posts, show this ABC category\'s name and link
                if ( $query->have_posts() ) { ?>

                <li><a href="<?php echo $abc_cat_link; ?>"><?php echo $abc_cat->name; ?></a></li>

                <?php } ?>

            <?php endforeach; ?>
            </ul>
        </li>
    </ul>

<?php endforeach; ?>