Group owner cannot filter by name when managing group memberships

A user who is the owner of a CoGroup and who has no other privileges (is NOT a CO admin, is NOT a COU admin, is NOT a platform admin) cannot filter on names when trying to manage group memberships and add somebody to a group.

An example is a POST sent to

https://registry-test.xsede.org/registry/co_group_members/search

with data (not including the token...)

data[CoGroupMember][co_id]: 2
data[CoGroupMember][cogroup]: 165
data[search][givenName]: Leslie
data[search][familyName]:
data[search][mail]:
data[search][identifier]:
data[search][status]:
data[search][members]: 0
data[search][owners]: 0

The result is a 302 and the flash set to "Persmission Denied".