=CALCULATE (
DISTINCTCOUNT ( AdDetails[adnumbr] ),
CALCULATETABLE (
SUMMARIZE ( AdDetails, AdDetails[adnumbr] ),
ALL ( titles ),
USERELATIONSHIP ( AdDetails[ttlname], 'FilterTitle'[filter filterttlname])
)
)
It doesn't seem to like the filter function next to filterttlname
There is no filter function in your formula. There is a USERELATIONSHIP that is using a relationship override between the AdDetails table and the 'FilterTitle' table. Is that what you intended? Have you created the inactive relationship in the data model?
=CALCULATE (
DISTINCTCOUNT ( AdDetails[adnumbr] ),
CALCULATETABLE (
SUMMARIZE ( AdDetails, AdDetails[adnumbr] ),
ALL ( titles ),
USERELATIONSHIP ( AdDetails[ttlname], 'FilterTitle'[ filter filterttlname] )
)
)
The word FILTER can be a function, but only if you use it right. The first occurrence of FILTER it is encapsulated in single quotes ie 'FilterTitle'. In this case, it is not a function but a part of the table name. In the second use of the word FILTER you have it encapsulated in square brackets. in this second case it is part of a Column Name that belongs to the table mentioned previously. If you want to use FILTER as a function, then you should not encapsulate it this way and always use the arguments that go with the function
FILTER(TABLE, filter expression)