The Diplomatic Session (basically a global meeting to negotiate a treaty(ies)) on the future convention on the recognition and enforcement of foreign judgments in civil or commercial matters will begin today and will end on 2 July 2019. This marks a milestone for the Hague Conference on Private International Law (HCCH) as the latest meeting of the Diplomatic Session was held more than 10 years ago, in 2007, on the Child Support Convention and its Protocol.
Not all preparatory documents are publicly available but the ones that are can be consulted here. See in particular the document on common courts, which refers to the Benelux Court of Justice and the future Unified Patent Court. The European Union has rightly clarified that the Court of Justice of the European Union is not a common court for the purposes of this Convention because the European Union would be able to join the treaty as a Regional Economic Integration Organisation (see Art. 27 of current draft), and hence its judgments would be within the scope of the Convention (see Annex II, paras 17 et seq.).
Please note that the meeting above-mentioned is open only to delegates or experts designated by the Members of the Hague Conference, invited non-Member States and International Organisations that have been granted observer status.