Pivot table reference formula

hello,

im trying to use the getpivotdata formula in excel 2013 to grab the YTD total for given amounts in each period of data. I'm not sure how to reference this in a formula since the Grand total column is not a specific column in the pivot table data. Here's a better picture of what I'm referring to below.

Expense category Period Grand Total(YTD)
1 2 3 4

Architecture:

Consulting exp $ ... $ ... $ ... $ ...
Hardware Exp $ ... $ ... $ ... $ ...
Depreciation $ ... $ ... $ ... $ ...

IT Operations

Consulting Exp $ ... $ ... $ ... $ ...
Hardware Exp $ ... $ ... $ ... $ ...
Depreciation $ ... $ ... $ ... $ ...


Basically I'm trying to grab the grand total column for each individual Business Area/expense amount in that area. I have the following formula setup that is able to grab the specific expense items for each business are. I just don't know how to syntax the grand total(YTD) column.

=IF(ISERROR(GETPIVOTDATA("Amount",Actuals!$A$4,"Period",'Period 4'!N$1,"IT Leaders",'Period 4'!B$50,"GL Map2",B51)),0,GETPIVOTDATA("Amount",Actuals!$A$4,"Period",'Period 4'!N$1,"IT Leaders",'Period 4'!B$50,"GL Map2",B51))