DAX function

FILTER — DAX function reference

Return rows matching a condition.

Syntax

dax

FILTER(<table>, <condition>)

dax

FILTER(Sales, Sales[Amount] > 1000)

→ A table

FILTER is needed here because the condition compares two columns, which a simple boolean filter argument can't express.

dax

CALCULATE(SUM(Sales[Amount]), FILTER(Sales, Sales[Amount] > RELATED(Product[TargetPrice])))

→ Sum of orders sold above the product’s target price

Pairs FILTER with ALL to build a modified filter that ignores the report’s current selection.

dax

FILTER(ALL(Product), Product[Category] = "Bikes")

→ All Bikes products, ignoring the visual's own category filter

Iterates row by row. Inside CALCULATE prefer a simple boolean filter when you can — FILTER is slower.
FILTER always does a row-by-row scan of its table argument, so filtering a huge fact table directly (FILTER(Sales, …)) inside CALCULATE is much slower than an equivalent simple boolean filter like Sales[Region] = "West" — reserve FILTER for conditions a boolean filter can’t express.
FILTER(Sales, …) inside CALCULATE further restricts whatever filter context already exists on Sales rather than replacing it — combine with ALL if you need to start from an unfiltered table.

From Filter context