Closest Hydstra is get_groups(), neither seem particularly useful.
Might make getStationList(), getTimeseriesList() and getTimeseriesValues() easier, though not obviously by much.
Note that 'the group identifiers are returned as group_id but specified in getStationList, getTimeseriesList, getTimeseriesValues, and getTimeseriesValueLayer as stationgroup_id, parametergroup_id or timeseriesgroup_id' per docs