Can you please give a bit more context about what you are trying to do in this expression?
If this is a chart expression and you are trying to reference a previous column (Column(1)) then I'm afraid that you can not do this in Set Analysis. You will need to repeat the expression in the Set Analysis, perhaps using dollar expansion.
Also, if you are trying to match the text Capability (rather than the value of a field called Capability) then this needs to be in single quotes.
Note as well that the trim statement will trim the whole output (eg. only the start of the first line of text and the end of the last). If you want to trim all of the values you need to trim the Supports field inside the Concat.
The best thing to do with set analysis statements is to start without any Set Analysis and then add in each field at a time to check what it does to the output.