请问这句话中的that of 在句子中是什么成分?

That of 在这里可以被换成 a relationship of
这里就是代指 relationshiop,因为你连续使用两个 relationship 就冗杂了.
that 在这里是代词.
Primarily,the banker-customer relationship is a relationship of debtor and creditor--who is which depending on whether the customer's account is in credit or is overdrawn.
意思是：银行与其顾客的关系相当于债主和借贷人的关系——到底谁是债主,谁是贷款人,这取决于顾客的账户有盈余还是已经透支.
这是新概念里面的吧.