Management and HR groups spend a lot of time talking about “engagement”， which comes down to getting employees excited about the work they’re doing and its contribution to the company.

　　管理和人力资源群体花费大量的时间来谈论“参与”，激发雇员对工作和为公司贡献的兴趣。

　　主句：Management and HR groups spend a lot of time talking about “engagement”;

　　定语从句1：which引导的定语从句which comes down to getting employees excited about the work they’re doing and its contribution to the company.定语从句修饰先行词engagement，关系代词which在从句中作主语;about后接宾语，the work and its contribution

　　定语从句2：they’re doing 修饰先行词work，关系代词that/which在从句中做宾语，可以省略。