我的问题是如何在我的父列中获取Null，以便在我的BusinessLine专栏中说明什么。
Parent BusinessLine Team AgentName
NULL Member Service NULL Hay,Kelly
NULL Member Service NULL Towson,Travis
NULL Member Service NULL Wein,Kenny
NULL Member Service CPO Staff Clark,Jessica
Resource HR A Bains, Randi
Resource HR A Christian,Beth
Resource HR A Carter,Jessie
Resource HR A Cline,Sara
Resource HR A Coleman,Nina