hello @stijn.devriendt, welcome to the Tulip Community!!
your assumption that Variables are cleared on completion is correct, however this can be easily changed by removing the ‘Clear on Completion’ option on the Variable:
do you think this option will work for you??
alternatively, you can add another Interactive Table, link a Table Record Placeholder, and use that as the filter for your main Interactive Table. it would be similar to this, except having an Interactive Table instead of the Text Input.
let us know if wither of those solutions will work for you!!