In our projects, we have several slips open in parallel, but when it comes to invoicing we don't want the various slips listed in the invoice. Our preference would be to have one item for all timed slips and separate items for all other expenses. However, when I have tried working with Group By in the invoice generator I can't seem to come up with a way to summarise only the timed slips. Am I doing something wrong? If this is a problem, is there a known way around it?
