calculate sales base on last price lowering date

[Wadda7AboUdai]

Hello every one 

I want to calculate  the qty and sales for every item base on last lower price date until today and the calculation filtered by every branch as the following 

itemid	lastlowerpricedate	oldprice	newprice	sales qty	sales	branch
01	01-01-2023	100	50	10	500	01
02	22-03-2023	70	30	22	660	02

Note : the seles should start  claculate from the lastlowerpricedate for each item and ignore any sales before the lastlowerpricedate

I have these tables 

ITem Table

itemid	name
01	toy
02	t-shirt

lowerpricetabel

item	lower price date	old price	newprice	qty	branch
01	01-01-2023	100	50	23	01
02	01-02-2023	120	70	222	02
02	22-03-2023	70	30	27	01

sales Table

itemid	sales	qty	date	branch
01	200	5	01-02-2023	01
01	300	5	13-02-2023	01
02	660	22	01-04-2023	02

[johnt75]

Try

Sales since lower price date =
VAR SummaryTable =
    ADDCOLUMNS (
        VALUES ( 'items'[item id] ),
        "@lower price date", CALCULATE ( MAX ( 'lower price table'[lower price date] ) )
    )
VAR Result =
    SUMX (
        SummaryTable,
        CALCULATE (
            SUM ( sales[sales] ),
            DATESBETWEEN ( 'Date'[Date], [@lower price date], TODAY () )
        )
    )
RETURN
    Result

[Wadda7AboUdai · Accepted solution]

Thank you @johnt75  for your reply 
I used this measure which I got from microsoft being chat 

Sales = CALCULATE(SUM(Sales[sales]),
FILTER(Sales, Sales[Itemid] = MAX(lowerpricetable[itemid]) &&
Sales[branch] = MAX(lowerpricetable[branch]) &&
Sales[Date] >= MAX(lowerpricetable[date])))
it works with me fine .

thanks