Question

One of the men held the view that what the book said was rig

Answer 1

One of the men held the view that what the book said was right.

that 是引导一个同位语从句,陈述view 的具体内容的

what the book said 这是个what 引导的名词性从句,在that--同位语从句中做主语,即主语从句

全句意为：

他们其中有个人持这样的观点,即书中所说的是对的