I am trying to pass list of columns into the dataflow and do a column match but it's throwing the error - Column functions are not allowed in constant expressions

for this I tried to work around first of all there are few things which you need to cross check few things. byName() is a column function, and $columnList is a parameter (constant expression) — and ADF doesn’t allow mixing these in a direct boolean expression inside the column pattern rules or derived column mappings. Below is the error you are getting when I tried to do the same way you did.

First cross check your dataset connection is successful. Make sure you checked first row as header.

Then in the derived column use the below expression.

You can check the output.