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Go to the filter you want to add/remove items to/from.
Click on Add on the right of the overview table.
A modal will open. Add/remove the items you want to add/remove.
Click on Submit.
Your changes are now visible in the overview but are not yet saved.
In order to save the chages click on Save.
In oder to go back to the previous state of the overview click on the … button and on Discard changes.