I don't follow what you mean by 'group is hidden'. If you want some indication that a possible group has no members - e.g. no customers whose names begin with a Y - then this is not easy in Crystal. One way is to do running totals for all possible groups and then put them in the report footer, which is long-winded but works.
It also helps if you say which version of Crystal.
Madawc Williams
East Anglia, Great Britain