An optional filter consisting of a single group name. The
filters limit the groups returned based on their parent-child
relationship with the specified group. If no filter is
specified, all groups are returned.
A group name:
"projects/{project_id_or_number}/groups/{group_id}".
Returns groups that are ancestors of the specified group. The
groups are returned in order, starting with the immediate
parent and ending with the most distant ancestor. If the
specified group has no immediate parent, the results are
empty.
A positive number that is the maximum number of results to
return.
