Related to the organization structure, at which structure we have two chains of command?

In Matrix Organizational Structure, there are two chain of command. 

Matrix management is the practice of managing individuals with more than one reporting line (in a matrix organization structure), but it is also commonly used to describe managing cross functional, cross business group and other forms of working that cross the traditional vertical business units – often silos - of function and geography.

For example, all engineers may be in one engineering department and report to an engineering manager, but these same engineers may be assigned to different projects and report to a different engineering manager or a project manager while working on that project. Therefore, each engineer may have to work under several managers to get his or her job done.

Thanks for the invitation

Well.....i believe it,s in

matrix organizational structure

It is matrix organization, this happend usually in projects.

In a matrix structure

.In  structure of organization , “chain of command” pointed to a hierarchy   of company of reporting relationships from the bottom to the top of an organization. 

 The chain of command not only establishes accountability, it lays out a company’s lines of authority and decision-making power. A proper chain of command ensures that every task, job position and department has one person assuming responsibility for performance.

I agree with all experts reply, i.e, in Matrix organization structure.

Matrix and rest I agree to all

In an organizational structure, “chain of command” refers to a company's hierarchy of reporting relationships -- from the bottom to the top of an organization, who must answer to whom. The chain of command not only establishes accountability, it lays out a company’s lines of authority and decision-making power.

Project Manager

One way of departmentalization is almost always according to projects or programs, the other usually being either disciplinary or functional.

Chain of Command refers as hierarchy. Project Manager act as leader of project who lead and control project team. On the other side he is answerable to senior management.

A project team and an engineering team under the common supervision of operations director/manager. y Project team lead by project manager and the technical team by engineering manager.Both teams should have an SPOC for inter relations. Hope this helps !!!

Matrix Organizational Structure has two chain of command.