Need to sum subsets of rows based on values in another column

[Anonymous]

I am trying to sum up chunks of rows within a specific column based on the values of another column. I have been trying to use the filter function but I am not trying to sum based on one unique value but rather an array of unique values in the reference column:

I would like like to sum up all the rows in column 'PPV Spend' that have same 'Plant_Mat' code and return that value in a new column.

[Anonymous]

Total PPV Spend Within Same Plant_Mat = -- this is a calculated column
var __currentPlantMat = T[Plant_Mat]
var __sum =
	SUMX(
		filter(
			T,
			T[Plant_Mat] = __currentPlantMat
		),
		T[PPV Spend]
	)
return
	__sum