Who's SO/CO in the separation process?

Who's SO/CO in the separation process once we resign? How can we see their details? In the i Talent I see the separation process is completed by PL, Second Level Approver and HR but next it's pending with SO/CO.

And if my direct reporting manager has confirmed and promised to give me early release, should I believe on him, he's been always very helpful and honest. Is there any other dept in tTCS who can cause problems in early release even if approved by manager?