WordPress custom post type queries

I'm using custom post types and listing them in single-[customposttype].php?type=example

<?php if (have_posts()) : while(have_posts()) :  the_post();the_content(); endwhile; endif; ?>

Now I have 2 different custom post type "customtype1" and "customtype2". "customtype1" is top category for "customtype2". When I add a new post on "customtype2" select category from metabox(I have a selectbox which listed "customtype1" posts.) in "customtype1" list. My question is how can I use a query for listing customtype2 posts which belongs top category page(single-customtype1.php)