how do I find a field on a report that I can't see?

I have a main report and a sub report. The sub report has a parameter that the main report does not have. I can't delete it because it is somewhere on the report but I can't find it.

ver 14.0.12.1946

I exported to a report definition and scanned it for the field name but nothing was there. Where else could it be?

Thank you very much!!!