The Court of Justice delivered on 13 July 2023 its judgement in case C‑87/22 (TT v AK), which is about the interpretation of Article 15 Brussels II bis:

“1. Article 15 of Council Regulation (EC) No 2201/2003 […] must be interpreted as meaning that the court of a Member State, which has jurisdiction to rule on the substance of a case on the matter of parental responsibility under Article 10 of that regulation, may exceptionally request the transfer of that case, provided for by Article 15(1)(b) of the regulation, to a court of the Member State to which the child has been wrongfully removed by one of his or her parents.

2. Article 15(1) of Regulation No 2201/2003 must be interpreted as meaning that the only conditions to which the possibility for the court of a Member State with jurisdiction as to the substance of a case in matters of parental responsibility to request that that case be transferred to a court of another Member State is subject are those expressly set out in that provision. When examining those conditions in respect of, first, the existence in the latter Member State of a court better placed to hear the case and, second, the best interests of the child, the court of the first Member State must take into consideration the existence of proceedings for the return of that child which have been instituted pursuant to the first paragraph and point (f) of the third paragraph of Article 8 of the [1980 Hague] Convention on the Civil Aspects of International Child Abduction […] and in which a final decision has not yet been delivered in the Member State to which that child was wrongfully removed by one of his or her parents”.

Source: https://curia.europa.eu/juris/document/document.jsf?text=&docid=275389&pageIndex=0&doclang=EN&mode=req&dir=&occ=first&part=1&cid=4466841