Newer than 90 days question

Question

I have a report I am creating for a medical clinic using date and procedure code fields.
I need to find all patients who had exactly 2 injections in the same eye, but none of the injections FOR THAT EYE can be older than 90 days.
***I cannot just filter out all injections older than 90 days because if the patient has EVER had an injection in that eye before the 90 days, they need to be excluded from any results regarding that eye (even if they had an injection in that eye in the last 90 days).
Here is an example of what I need:
Patient Name      Procedure Date   Procedure Code    Modifier field (Which Eye)
John Doe               7/1/2014               12345                   Rt
John Doe               7/10/2014              12345                  Rt
NOT THIS  (even though patient had 2 injections in same eye in last 90 days, the OLDER injection disqualifies the patient completely)
Patient Name      Procedure Date   Procedure Code    Modifier field (Which Eye)
John Doe               3/1/2010                12345                  Rt
John Doe               7/10/2014              12345                  Rt
John Doe               7/17/2014               12345                 Rt
Any help would be greatly appreciated!
Thanks.

Answer 1

Glad it worked!
Minimum({Procedure_Date},{Modifier}) : Extracts the earliest date in each Group which is the 'Modifier'.
Over90Days: is a built-in function that returns True if the date it's being compared with is over 90 days old and false when the date is younger than 90 days.
Put all this together, and we're simply trying to check whether the earliest date in each group is less than 90 days or over. If it's over, the Group Selection Formula just filters that group out.
-Abhilash