It's tough to get a rolling value like that as far as I can tell. The closest I could really get to this, directly in CJA, was to create a derived field where you return some value if the dates are between some values:
The only thing here is that there's not really a way to make things relative to the current day or time so that you could get a rolling age as time goes on. I'd be interested if someone was aware of another method of getting to a rolling date against a date field in AEP, directly within CJA. It might not be a bad idea to even request this as an update to derived fields in CJA.