Table with values switch to rows, difference, impact columns

Hi Evelin_  - you can create the Difference (pp) measure

Difference_pp =
VAR CY = [CY selection]
VAR Base = [Base selection]
RETURN
FORMAT(CY - Base, "0.0") & " pp"

you want the impact to be a function of the pp difference and some weighting

Impact =
VAR pp = [CY selection] - [Base selection]
-- You can apply a custom logic here
-- e.g., multiply by a fixed factor, or lookup a weight from a table
RETURN
pp * [SomeWeight] -- Or a hardcoded number like 200

If the weight is fixed or based on the row context

Impact =
VAR pp = [CY selection] - [Base selection]
VAR impactFactor =
SWITCH(
SELECTEDVALUE('MetricsTable'[Metric]),
"Total", 200,
"Promo", 100,
"xx", 10,
0
)
RETURN
pp * impactFactor

Hope this helps.