How to Stop Final Approval at 1 level below CEO in the PO approval

Summary:

we have departments have different number of levels,

like the requester department is equal "IT" so it has like 4 level hierarchy and the last level before the CEO is "Director"

But if the requester department is equal "Finance" so it has like 5 level hierarchy and the last level before the CEO is "Chief"

and what we want to add the approver to be dynamic and to get the level 5 only in the approval

I mean that if any department has the chief so it will appear only in the approval and we dont need the directors to appear

Appriciate if you can help.