I can retrieve historical financial statement data with refinitive.data.get_history funciton by specifying universe with oa_org_permid from DataScope bankloan database.
However, for a public company like Alphabet, using the parent company's PermId returns nothing, while using GOOG.O can retrieve all the financial data.
The question is why I cannot use the Company PermID 5030853586 to retrieve Alphabet's financial data.