Knut, make a duplicate of your set (or combined field in V8) and put both fields on the filter shelf. Set one to include all values. Set the other to exclude values, and check all the items you want to get rid of. Now show both quick filters and set the one that includes values to 'Only Relevant Values'. Now when you compare the lists you'll see that all the items that have been crossed out on the exclude list are missing from the include list. Hide the exclude quick filter and you're done:
Your "tweek" sorted it out quite nicely.