DAX HELP

Hi,

I am trying to replicate the tutorial found here http://www.daxpatterns.com/basket-analysis/ changing it to my code.

The probllem is it does not like the last filter function and doesnt recognise it as a function...Any ideas.

=CALCULATE (
    DISTINCTCOUNT ( AdDetails[adnumbr] ),
    CALCULATETABLE (
        SUMMARIZE ( AdDetails, AdDetails[adnumbr] ),
        ALL ( titles ),
        USERELATIONSHIP ( AdDetails[ttlname], 'FilterTitle'[filter filterttlname])
    )
)

Thanks

C