If I'm following correct, we need to be able to report of all the records that where closed in previous months, and any records that close this month. Additionally you'd like to include in the current month report any records that don't have a close date, thus still 'open'.
If that is the case (or close to it) you will want to make a 'formula date' field, call it something like [Month Closed]. That field will either reflect the first day of the month it was 'closed' or the first day of
this month if it is still open.
If(IsNull([Close Date]),
FirstDayOfMonth(Today()),
FirstDayOfMonth([Close Date])
)
Once you have this new [Month Closed] from the formula, you can make any reports you'd like and easily have good groups and sorting display easily.
