my @selected = ( @data );
while (1) {
   print "Search by city, table or group? (or D for done)";
   chomp($key=<>);
   last if $key eq 'D';
   my @choices = map { $_->{$key} } @data;
   print "Choices are: ", join(", ", sort @choices), "\n>";
}
... print report on selected data ...