This option allows you to set the depth at which BRU will work during its restore process. Files more then the -U(#) levels will not be processed. For example, if the current directory is /home/webmaster, -U0 (zero) will only restore the files and directory nodes in the /home/webmaster directory. While the directory node (name) will be restored the files in side each directory will not be restored.
With a level of -U2 (two), BRU will restore /home/webmaster/test, /home/webmaster/test/runone, /home/webmaster/test/runtwo, but not restore /home/webmaster/test/runone/demo1. In this configuration BRU can be used to easily restore a subdirectory from a total system backup.