Hello @neekstressed,
and welcome to KNIME Community!
Controlling Table Creator node with flow variables is a bit cumbersome and I would suggest to stay away from it. Especially when there are other (better) options for your use case.
So if I got your process right you should first get unique values and for it you can use GroupBy node as you did but also Duplicate Row Filter node (which is more intuitive and has a bit more options if you’ll need it in future). Also after it you won’t need Column Filter node probably. Then you need to present users with option to input correct mapping for season column. Node you can use here is Table Editor. Missing functionality in it is that you are unable to create new columns (and rows as well I think) with it so you should create it before and it’s best to be empty. This you can easily do in Table Creator node but as your list probably doesn’t come from it see here how to easily add new column with missing values to your data table (missing values in KNIME are denoted as red question marks).
See here a screenshot of suggested idea:
Then you’ll probably want to correct starting dataset and for it you can use Cell Replacer node.
Give it a try and if any questions/issues feel free to ask. Hope this helps!
Br,
Ivan