Assuming that:
- slug of your taxonomy is
movie - slug of your term is
b - you are using pretty permalinks
- your website is accessible at: www.example.com
You can see a list of all posts which have been assigned this specific term under this taxonomy by going to:
www.example.com/movie/b/
This page will display posts from all custom post types to which this taxonomy has been added. So, if you have added this taxonomy to just one post type then it will automatically list posts from just that post type.
You can control the display of these posts by creating/editing an appropriate template for this taxonomy or even this specific term according to the hierarchy given here: http://codex.wordpress.org/Template_Hierarchy#Custom_Taxonomies_display