Is it permissible to borrow from an Islamic bank in one country to invest the amount in deposits and savings certificates with an Islamic bank in another country, and is Zakat obligatory on the borrowed amount from which only a quarter has been repaid?

It is permissible to borrow from an Islamic bank if it conducts a benevolent loan (Qard Hasan) operation. It is also permissible to engage with it in a Murabaha sale for the one who commands the purchase, or Tawarruq, in order to obtain cash. There is no objection to investing the money after obtaining it in any Islamic bank that adheres to Sharia guidelines.