CALCULATETABLE
Can be used to convert a table to another table by adding/removing some filters.
This is useful when calculating total based on row level values.
Example
VAR __tot = SUMX(
CALCULATETABLE (
SUMMARIZE(
Sales,
ProductCategoryTypes[ProductCategory],
Stores[Region]
),
REMOVEFILTERS(Quarters[Quarter]),
Quarters[Quarter] <= __qtr
),
[Row_Level_Measure]
)