Sorry for the late reply. Tuesday I've to do the support.
I added 2 screenshots clarifying the challenge.
In the table I want only the Id's for which there are no visits registered. I tested some more and filtering on target1 and target1, both customer classifications, seems to work. Filtering on Date gives me problems. I tried several variations on the formula in the table without succes.
Also doens't work as soon as I start filtering on year.
Customers and Visits are connected through CustEmplDate. I want to show the customers with no visits in the year 2016. For the customer for whom there is no visit, there is also no date and thus no year. By filtering on date, all the customers without visit are already removed by the selection.