Managing up (helping people above you in the org understand what they need to be doing and how they need to be interacting with you) is an essential part of being a great leader in any company.

However, it can often be quite difficult.

Why?

Sometimes, your leadership is simply and generally unreceptive to most new ideas or perspectives from anywhere (bad!)
Sometimes, the very thing you've noticed is a sore point (or a point of weakness) for your leaders - so they don't understand or appreciate the thing you are pointing out (blind spot!)
Sometimes, they might feel like the thing you're pointing out is simply "not your job," or you lack the context to make a coherent observation (who asked you??)
Sometimes, they might feel like you are selfishly advocating for your area/perspective/department at the expense of others - even if you might be objectively right (he's just biased!)
Sometimes, you simply don't have the authority to build consensus with your peers - so a decision never gets made.

Therefore, sometimes, the answer is that you need a 3rd party perspective (external contractor, advisor, mentor) to help.

Lean on them.