Identifies whether or not a user belongs to a group.
isusermemberofgroup( username, groupId )
username: (Text) The username to check for group membership.
groupId: (Group) The Id of the group.
true when the user belongs to the specified group, except when security rules prohibit users from knowing this information.
For example, this function always returns false and never true (for the purpose of securing membership awareness) in the following instances.
When the expression function is passed a high privacy group as a parameter AND is executed within the context of a basic user who is not a group administrator AND is passed the username of another user, it returns false instead of true.
A basic user is not allowed to know whether another user is a member of such groups.
You can copy and paste these examples into the Expression Rule Designer to see how this works.