Hello Dear Kyriakos,
The naming convention I use is the following:
Greek nationals have only first names. Any second name is considered a second first name, not a middle name, and they are separated by " - ". So for example Κυριάκος - Απόστολος. The same goes for last names.
I try to add the name written with Latin characters so it is searchable. Greece uses ELOT 743 to transcribe the names. Cyprus allows nationals to choose their spelling, so for that, I suggest you research the Latin version of their name.
