For context, Madalyn wanted to filter Tasks twice on the same field (actualCompletionDate), but as Rich pointed out, Workfront does not (As Designed) allow that, "swallowing" one of the directives upon save.
However, in a pattern similar to the more familiar textmode "OR" concept that does allow the same field to be used in two or more separate clauses, Workfront does recognize and correctly execute and "AND" against the same field, which in Madalyn's case would be as follows:
AND:a:actualCompletionDate=$$TODAYb-2m AND:a:actualCompletionDate_Mod=between AND:a:actualCompletionDate_Range=$$TODAYe-2m AND:b:actualCompletionDate=FIELD:plannedCompletionDate AND:b:actualCompletionDate_Mod=gt
Save until needed.
Awesome! Thanks so much for sharing, Doug. That is going straight into the text-mode vault for future reference.