I use manual payroll but this link may be helpful: 

https://help.quickbooks.intuit.com/en_US/kb/tracking-payroll-expenses-by-class-department-or-locatio... 

one more step to add for the report to be narrowed down to THAT class only 

• on the “Customize Report” tab also select the “Filters” tab
  •   Left column “Filter” select Class
  • On the next box over select the Class specifically from the drop down (Any or all)

You will note on the paycheck detail that the Class box is near the upper right corner.