Good question. I don't see a way to file a complaint with abp. However, if you really feel that your pediatrician has done something wrong, please start a conversation with him/her. Pediatricians are extremely interested in helping your child and can even suggest second opinions. The abp maintains specialty certification, the worst they could do was revoke certificaiton, but not a medical license to practice.
Complaint. The pediatric board will likely refer you to licensure board in your state. Unless the doctor lied about certification I do not believe it takes disciplinary action.
Complaint with ABP. They will look into the issue and direct it to the right agency depending on your complaint. The medical Boards of the states are the licensing agencies and are in charge of complaints and licensing the physicians.
Not much. The abp is a certifying agency not a regulatory one and is not generally held in high regard by practicing pediatricians.