The web services currently do not have a function that returns the groups associated with a grouping. This could be done by adding an optional parameter to the function core_group_get_groupings so that the groups associated with each requested grouping are also returned.

For example, this modification would be useful for a web service client that wishes to determine the teams and their members in a team assignment in the new Moodle assignment module. The mdl_assign table has a "teamsubmissiongroupingid" that links to the grouping which is associated with the groups/teams.