I know there are some really knowledgeable people here in the immigration matter.

Do you know if you require to complete I-864 (Affidavit of Support) if your I-140 has been approved and you have applied that on your own behalf under Extraordinary Abilities ?

To be a sponsor of an immigrant relative, you must be at least 18 years old and a U.S. citizen or a legal permanent resident. You must have a domicile in the United States or a territory or possession of the United States. Usually, this requirement means you must actually live in the United States, or a territory or possession, in order to be a sponsor. If you live abroad, you may still be eligible to be a sponsor if you can show that your residence abroad is temporary, so that you still have your domicile in the United States.
You should complete an I-864 Affidavit of Support when your relative has been scheduled for an immigrant visa interview with a consular officer overseas or when your relative is about to submit an application for adjustment to permanent resident status with the USCIS or with an Immigration Court in the United States.

Thanks but you missed my point...

Self Petitioned I-140 under extraordinary ability has been approved. It's only for myself. There are no dependents. I am already in the US. I understand the case now goes to National Visa Center. Do I have to get my employer/or someone to file affidavit of Support on my behalf ?

Thanks for clarifying! Since you are self sponsored, you do not need to file an affidavit for your self.
Only family based immigrants need to file an I-864!

Thank you... That helps a lot...