What are 3 levels in the Government that a contractor can file a protest against the Government during post award and when must it be file?

Can a Contract Specialist settle a protestwith acontractor during the post award process?

Can a Contract Specialist be given verbal authority to negotiate a dispute filed against the Government from a contractor and can they negotiate and render a Contract Specialist final decision based on the authority given to them by the Contracting Officer - and if so either why or why not?

Please support your answers citing APA the proper authority.