As I could understand, you would like to filter all rows
of those [Region] which the [person] belongs to.
This could be done with an aggregate Condition Filter on [Region].
1. Create a calculated field, say [person filter], like this:
IF FULLNAME() == [person] THEN 1 END
2. Place [Region] on Filter shelf and select options:
General -> Use all
Condition -> By formula -> Enter the following calc:
MIN( [person filter] ) == 1
Set the filter to Context.
3. Make a quick filter from [person]. Enjoy.