bbPress.org

bbpress only displays 2 levels, so when you click the 2nd level, you will get to see the lower down forums.

It is possible to code for lower levels, if you are happy with coding you’d be looking at

wp-content/plugins/bbpress/templates/default/bbpress/loop-single-forum.php

and some coding around bbp_list_forums()
to get a further loop

As for breadcrumb – yes by default you should have one , but themes can turn these off