I have a table of amounts and I need to filter it so that it only shows credits or negative numbers. When I use a if statement, it nulls or grays out the cells in the "amount" column that is a positive but does not hide the entire row.  I've also tried suppress null values and 0 values option but it doesn't work

I'm trying to use this set expression to create the filter but I'm getting an error: "Error in expression: ')' expected."

if($amount)<0, Sum(amount),0)