For over 6 years people have been asking for a method on the bbPress forum to have a good hierarchical url structure.

The issue lies in the way bbPress treated a thread a topic and a reply as seperate post types.

tested against latest bbpress as of today 12/04/16

Download and install as a plugin. please test it first and back up things in case of problems.

provided as is with no warranty at all treat this as an alpha release.

bbpress-vbulletin-permalinks

Most of the work goes to https://github.com/korobochkin/bbpress-permalinks-with-id for the original steps and the rest is hopefully history.