So - the issue is with our query fields in InfoPath data connections, we can only use equivalence. You won't be able to check if something is less than today minus 7 for example. If you are using on-prem you might be able to use a REST query for this, using the listdata.svc. I'm trying to think of an approach that can use a regular list query and not need to use anything but equals - I was thinking about a calculated column with just the year and month from the created date, then you could use that for equivalence... like your calc'd column had 201907 in it... but then you need to be careful at month or year change. I suppose if nothing is returned, you could try the prior month (or year) in your query.
Hilary Stoupa
