How to navigate through nursing career?

I am trying to find an ambulatory type nursing position. I have 33 years of RN experience in variety of nursing fields. I have my MSN in nursing education. It seems with every area of nursing there is some type of certification that is expected and this seems to rate more than having a MSN!!! How can one break loose from being labeled and seeking a different area of nursing employment and is it truly necessary to have a certificate in this specialty or should I just pick one to become certified in??? Does that really make me more marketable??