Going for my first manager position, what certs are most valuable.

Sr. Sys admin 18 years experience in the field, on a succession path to lead the department at my current company.

I have ITIL currently, but what courses and certifications would aid me best to move to that level of corporate leadership? Not just for the resume, but in terms of value and knowledge.

Agile? Lean? A C.I.M cert and membership?

Our company is in manufacturing and the plant side uses lean six sigma so im thinking at least yellow belt in that.

Any advice?