In Portal, it's easy to get a list of items that are shared with a group, i.e. https://example.com/portal/sharing/rest/search?q=group:f830a49853d641d7855f424af57a8f7c
Is there a way to get a list of items that are not shared with any group?
q=owner:username AND access:private comes close, but items can also be shared with the organization or public, and not with any group
