SSRS 2008 Inscope / Percent to Total

Over the past couple of weeks I have been asked several questions about InScope function in SSRS 2008. It is a very useful function that allows for aggergations at different group levels in a report. This is helpful when trying to calculate a dynamic percent to total by a parent group.

Here is an example of how to use Inscope:
Territory Total of 2500 appts
District Total of 125 appts
what is the percent total?

=iif(iif(InScope("Territory", count(Fields!.Appts.Value,"Territory"),0) = 0 , 0,
count(Fields.Appts.Value) / iif(InScope("Territory"), count(Fields.Appts.Value, "Territory"),0))

Result = 5%