Filter Table in special way based on column from another table

Click here to download solution

Download PBIX 

How it works ...

Create a related and unrelated copy of shop table.
Use one to pick (slice) and the other to display.
Otherwise it is complicated to slice a shop and display the other shops ! 

Create a measure

Is Valid Customer = 
VAR pickshop = SELECTEDVALUE('Shop picklist'[CofeeshopID])    -- getspicked shop id
VAR customers =                                               -- get list of customers who visted picked shop    
CALCULATETABLE(
    VALUES(Sales[Customer]),
    ALL(Sales),
    Sales[Coffeeshop ID] = pickshop)
VAR thisshop = SELECTEDVALUE(Sales[Coffeeshop ID])             -- get shop being output
VAR thiscustomer= SELECTEDVALUE(Sales[Customer])               -- get customer being output
RETURN
SWITCH(TRUE(),                                                 
thisshop = pickshop, "N",                                       -- ignore picked shop
thiscustomer in customers, "Y"                                  -- flag customers who are in the list
)

Fiter you reports using the measure

Pay great care to use the correct table and field names.
iI you use the shop or the customer from the wrong table then the solutoon wont work.
Download my example and copy the code.

Thanks for the clear description of the problem with example data. I wish everyone did that!

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