1) the Raw Data sheet contains some time series data for a couple of securities in a portfolio
2) I created the calculation called "Age" and then set up the sheet called By Deal. This sheet produces the correct results. Note for each deal when Age = 1 the value is null (we don't have the data for this period).
3) The problem begins when I remove Intex_Deal_Name from the viz (see the Aggregate) sheet. It looks like Tableau has now added the balances based on date rather age. I was expecting the that sum for:
Age =2 would be 3,798,366,862
Age =3 would be 3,728,017,452
Age = 4 would be 3,637,460,112
and so on (these are the values you would get by adding up the 3 displayed values across deals for each age).