Paying back the same amount one loaned in a foreign currency even thought the value is more

I took a loan of 8000€ 7 years ago from a couple of close family members for going abroad for education. At that time the Euro to PKR rate was 1€=114PKR. Now after a couple of years, I am capable of returning that amount and I returned the money to all of them except to one person. He sent the money to my father in Dirhims (4000 AED at that time which was equal to 150,000 PKR) so my father added these PKR to sponsor Euros for my education. Now 4000 AED equals to around 270,000 PKR.

Should I return the Dirhims with the current currency conversion or at the rate at which the money was borrowed?

I also returned the PKR on the same rate which I borrowed. For e.g. my father borrowed 400,000 for me from one person and I returned 400,000 PKR directly. But this is confusing as the person sent 4000 AED to my father at that time which equaled to 150,000 but now if I convert 4000 AED then PKR would easily be double. So my question is how much money should I return?