分析以下句子结构,of what would 这个是什么结构,怎么翻译

in 1901是时间状语
the two 主语
opened 谓语动词
their first shoe store 宾语 （不细分了）
in downtown,Seattle 地点状语
This 主语
was 系动词
the start of what would become the retail legend of Nordstrom.Inc.表语
the start of sth..的开端
what would become the retail legend of Nordstrom 是介词 of 的 宾语从句
供参考,祝进步!what would become 的what 修饰的是什么呢？用来引导从句，在从句中做主语 I can't stand what is happening. 眼前发生的一切简直让我无法忍受。还可以做宾语 i can hardly understand what he said just now. 我几乎就听不懂刚才他说的话。供参考，祝进步！