1) There is an active relationship between the Time Sheet and workload tables.
2) Being totally ignorant of your data, I have no idea, but the value "Job Time" in the second filter looks suspiciously like a column name rather than a valid value for a Job Code column. Is that really what you intended there?
If neither of these is the problem, try just throwing up a table with your time sheet data in it and using the Filter side bar to limit your data as you're trying to do in your formula. If you get an empty result there too, you know the problem is in the data and not your formula.