Your opposite number
Definition 1 of 1
Pro Tip 1/3Workplace Context
Typically used in professional or organizational settings to refer to a similar job role elsewhere. 
I'll arrange a meeting with my opposite number in the marketing department of our sister company.
Pro Tip 2/3Interorganizational Communication
Use when you need to interact with someone holding a parallel position in a different group or team. 
Could you get in touch with your opposite number at the client’s firm to discuss the details?
Pro Tip 3/3Collaborative Projects
Mentioned when collaborating across different organizations or departments on a shared project. 
For this joint venture, our project manager will work closely with her opposite number from the other company.