Application.IsCurrentWebUserInGroup (Access)

Gets whether or not the current user of a web database is a member of the specified Microsoft SharePoint Foundation 2010 group.

IsCurrentWebUserInGroup (GroupNameOrID)

GroupNameOrID: The name or identifier (ID) of the group.

Dim strGroupNameOrID As String: strGroupNameOrID = 
Dim booIsCurrentWebUserInGroup As Boolean
booIsCurrentWebUserInGroup = IsCurrentWebUserInGroup(GroupNameOrID:=strGroupNameOrID)