Show specific content on parent custom post type and all children

You could setup a condition based on post ID:

<?php if (is_page(12) || $post->post_parent=="12") { ?>

    <ul>
        Your Menu
    </ul>

<?php } else { ?>

    <ul>
        Another Menu (or put nothing here)
    </ul>

<?php } ?>

If you don’t know how to locate the post ID:

“Roll over any page, post or category with your cursor (while logged in and in the “manage” area of course), and the page, post or cat_id number appears in the progress bar in the bottom of the browser.” – http://wordpress.org/support/topic/where-is-the-post-id-number