How to set the approval for compensation plan to have multiple routes based on the employee

We have a requirement where we want the approval for the compensation to have different flows based on the employee grade.

For example approval for employee with grade A will have the following flow : 1- HR approval Only

approval for employee with Grade B will have the following flow: 1- Second level Manager approval. 2- After Second level manager approves it will go to HR for approval.

How can we implement this?