Calculating filter only for certain rows in a table

Hola Amigo

The problem is that your measure runs the TOPN calculation once per row in the visual, so with 25k rows it's running 25k times. The fix is to compute it once and reuse it.

The key trick is to make DAX cache the TopN result instead of recalculating it per row.

Something like this should be much lighter:
daxShowCompany =
VAR N = SELECTEDVALUE('TopNValues'[Ranks])
VAR TopNBrands =
CALCULATETABLE(
TOPN(N, ALL('unique_brands'[brand]), [SalesForChosenPeriods], DESC),
ALL('unique_brands')
)
RETURN
IF(
N = 0 || SELECTEDVALUE('unique_brands'[brand]) IN TopNBrands,
1,
0
)
Using IN instead of CONTAINS is also faster. The main thing though is making sure the TOPN runs against the brand table directly without being re-evaluated in item-level context.

Hi!   calamistratus 

You can try this