Redmine

Is it possible to add a user group filter on the spent time report details view to be able to retrieve time entries for all specific user groups on one page/report?

Our project is done by three groups (in this case three companys) that should be shown seperately in the same time report.
So far its only possible to add a member detail filter, not a group filter. We need to report hours per month per group (company). I grouped the users of each company at the administration/group panel into three groups so far. But there's no option at the time report site to sort the list per group. Is that possible somehow?

Thanks,
Lydia

Environment:
Redmine version 2.2.3.stable.11610
Ruby version 1.8.7 (x86_64-linux)
Rails version 3.2.12