How to create new custom taxonomy templete?

Have a look at this:

http://codex.wordpress.org/Template_Hierarchy#Custom_Taxonomies_display

I’m really not sure what you mean. The structure of the categories is set up when you enter them into the admin area, isn’t it? If you view the parent categories page you’ll see everything from the sub-categories included on that page as well. Or am I missing something else here?

As I said before…

If you view the parent categories page you’ll see everything from the sub-categories included on that page as well.

Using your example above, if you view the page for ‘abc’ you see all items for ‘abc’, ‘test’ and ‘test2’ on the same page.