多组和多用户的Firestore结构和规则

Question

我很难为Firestore中的多个组和用户设置最佳解决方案。

在下面您可以看到到目前为止的结构和规则，并且在一个小组要按名称列出所有成员之前，它运作得很好，应该如何设置规则？

或者您为我的设置推荐其他结构吗？

users: [
  "userId" {
     "name" : "Name",
     "groups" : ["groupId", "groupId", "groupId"]
    }
]

groups: [
  "groupId" {
     "name" : "Name",
     "members" : ["uid1", "uid2", "uid3"]
    }
]

contacts: [
  "contactId" {
     "name" : "Name",
     "owner" : "groupId"
    }
]

Firestore规则

function member(groupId) {
  return request.auth.uid in get(/databases/$(database)/documents/groups/$(groupId)).data.members;
}

match /users/{userId} {
  allow read; // <---  how to allow only same group members to read?
  allow write: if request.auth.uid == userID;      
}

match /groups/{groupId} {
  allow read: if request.auth.uid in resource.data.members;
  allow write: if request.auth.uid in resource.data.admins;
}       

match /contacts/{contactID} {
  allow read: if member(resource.data.owner);
  allow write: if member(request.resource.data.owner);
}