Hi @Waleed Saleem ,
Thank you for posting query in Microsoft Q&A Platform.
Thanks for asking query in english. But screenshot was not in english hence little unclear on understanding implementation here. It would be great if you share screenshot also in english along with exact requirement in aggregate which you are trying to acheive.
However, It seems you want to point a column name which is actually a value in parameter. If this is true, then kindly consider using byName() function in dataflow, which helps to refer to column name dynamically.
Hope this helps. Please let us know how it goes.