how do i find the child processes of a backup policy?

NBU 7.6.0.3

Windows Server 2008 R2 sp1

in the NBU activity monitor, you will see a backup policy starting and spawning several child processes. that is fine if there are only a single policy running. but if there are multiple instances of the same policy running and you want to cancel those child processes related to the failed parent process, how do i find out which?