SpiceDB is an open source, Google Zanzibar-inspired, database system for creating and managing security-critical application permissions.

SpiceDB

you mean something like 

```yaml
definition user {}

definition group {
    relation member: user
}

definition prompt {
    relation creator: user
    relation editor: user
    relation viewer: user
    relation groupViewer: group#member // added this

    permission can_view = creator + editor + viewer + groupViewer // add the groupViewer union
    permission can_edit = creator + editor
}
```

and then 

```typescript
    spicedbClient.lookupSubjects({
      consistency: {
        requirement: {
          fullyConsistent: true,
          oneofKind: 'fullyConsistent',
        },
      },
      resource: {
        objectId: promptId,
        objectType: 'prompt',
      },
      permission: 'groupViewer',
      subjectObjectType: 'group',
      optionalSubjectRelation: 'member',
      wildcardOption: v1.LookupSubjectsRequest_WildcardOption.EXCLUDE_WILDCARDS,
      optionalConcreteLimit: 0,
    })
```