I would rather not tell where the problem was 
In the floating filter button action the data source was set to item table instead of work table. Grrrr … small things. Changing this has solved the problem of creating User Specific and Single Value columns in the right table, as you suggested at the beginning and in your tutorial.
Now I am facing the biggest challenge: how to set the filter logic. In your tutorial you are dealing only with one filter choice. I have 8 of them so it gets tricky. I actually have no idea how to collect and combine all 8 selected filters options and then set a rule/filter to the Inline list (on the All items tab) what to display and what not.