The EU has a central bank. The European Central Bank and the national central banks together constitute the Eurosystem, the central banking system of the euro area. The main objective of the Eurosystem is to maintain price stability: safeguarding the value of the euro. The European Central Bank is responsible for the prudential supervision of credit institutions located in the euro area and participating non-euro area Member States, within the Single Supervisory Mechanism, which also comprises the national competent authorities. It thereby contributes to the safety and soundness of the banking system and the stability of the financial system within the EU and each participating Member State.

Your question would be better phrased as 'how do xxx and yyy participate...' That's also probably too technical a question for this forum - I don't know if there are any economists or financiers here.