Calculating Total Sales by Category (multiple lines with the same category)

[JAS2022]

I am trying to do a scatter plot visual that includes total sales by customer.  The way my dataset is currently setup; there are multiple lines for the same customer (all lines add up to the true total sales).  When I add sales to the scatter plot along with a slicer (that includes sales) to be able to view customers sales by a certain range, Power BI is not reading the true "Total Sales".  See example below on what is occuring.  

Customer A total sales = $9

Customer B total Sales = $3 

If I slice it to say anything less than $8 customer B should only show, but power BI is reading each individual line and showing customer A at $7.  Is there a way to create a formula or expression to where power BI would read Customer A at a total of $9 and B at $3 so that my slicer would work correctly?  

[amitchandak]

@JAS2022 , Create a numeric ?what if param and follwing measure

Total Sales = sum(Table[Sales])

GT Selected = sumx(values(Table[Filter]), if([Total Sales] >= [Parameter Measure] , [Total Sales], blank() ) )

https://docs.microsoft.com/en-us/power-bi/desktop-what-if