Grouped running total based on 2 columns|Power Query|Excel Forum|My Online Training Hub

Hi Again,

So following on from the grouped running total column thread and using Phils code (very tidy solution) I can get a running total around 1 column but what if you have a couple of columns to contend with  - Is this possible?

using the function already described by Phil / Mynda - fxGroupedRunningTotal

I've tried altering the query code but I'm getting an error saying RT only allows 2 parameters which you can see in the 1st line of the function code 

(altered query code)

BufferedValues = List.Buffer(Source[Amount]),
BufferedRegion = List.Buffer(Source[Region]),
BufferedCountries = List.Buffer(Source[Source]),

RT = Table.FromColumns(
{
Source[Source], Source[Region],Source[Period], Source[Amount],
fxGroupedRunningTotal(BufferedValues, BufferedCountries,BufferedRegion)
},
{
"Source",
"Region",
"Period",
"Amount",
"Running Total"
})
in
RT

So i'm guessing the function requires a bit of tweaking around the 'each try ' area and its a little bit beyond me TBH but has anyone done that on Phils code for the function ?

(values as list, grouping as list) as list =>

let
GRTList = List.Generate
(
()=> [ GRT = values{0}, i = 0 ],

each [i] < List.Count(values),

each try
        if grouping{[i]} = grouping{[i] + 1}
        then [GRT = [GRT] + values{[i] + 1}, i = [i] + 1]
        else [GRT = values{[i] + 1}, i = [i] + 1]

otherwise [i = [i] + 1]
,
each [GRT]
)
in
GRTList

Desired Output

once again - thank you - been on a steep learning curve this week