It's a little bit different, but here's how I would do it. On the project search pull in the list of tasks and hours, and on tasks pull in the revenue type, and on the hours pull in the entry date and the task ID.
Then, iterate thru the task list, filtering out any tasks that you don't want to know the hours for, and aggregate it into a simple list of task ID's.
Then, iterate thru the hour entries, filtering out for entry date, as well as checking to see if the hour's task ID is in the list you created previously, and aggregate those into a list of hours.
Then have a variable with sum({resulting hour list}).
This should give you the total number of hours that have been added onto tasks that are set to the revenue type(s) you want, and that were entered in the last month.
hours Variable in hours iterationoverall scenarioWorkfront project search collections settingsTask FilterHours filterTotal number of hourshour variable