parent child hierarchy filtering

[robinherrick]

I have a four level hierarchy, arranged much as per the example in F 11 17 from Chapter 11 of the Definitive Guide to DAX by Russo Marco and Ferrari Alberto. When I filter by name, it keeps the person and its parents, but I also want to keep the children of the filtered person.

The first measure is
BrowseDepth:=ISFILTERED (Persons[Level1]) +
ISFILTERED (Persons[Level2]) +
ISFILTERED (Persons[Level3]) +
ISFILTERED (Persons[Level4])

and the second is
PC Amount:=IF (
MAX (Persons[NodeDepth]) < [BrowseDepth],
BLANK (),
SUM(Sales[Amount])
)

The output table is the person's name and the PC Amount.

I cannot figure out how to do this by myself so any help would be much appreciated.

[robinherrick]

I forgot to say that I am working in Excel hence using ISFILTERED rather than ISINSCOPE