I asked this question about 2 years ago and Phil Wade replied that Datgel tool was needed, which we don't have. I noticed today that there seems to be a report overlay function in the Graph report and am wondering if that would work. To test, I set up a Rain table with date/time as keyset and then added a Precipitation field. I then created a report to just plot the rain data vs time and it works fine. However, when I try to use that report as an overlaid report in my groundwater monitoring graph report, it doesn't work. On preview in output, it does seem to be trying to do something different, but very quick box disappears which says something about moving to general drawings. And when the preview for the groundwater monitoring graph comes up, the rain graph does not show. Am I doing something wrong or is this not going to work.
I have created several overlay reports that work quite well for us and would be happy to take a look at what you are trying to achieve and help you find a solution, if there is one. I would need to be able to take a look at your library and input, so we could potentially setup a TEAMS meeting or other screen sharing option to go through it together. Respond here if you would like some help!