Kyiv is pronounced K-y-i-v, where “y” is similar to sound “i” in “silk” or “y” in “sync”.
Ukrainians pronounce it as K-y-yi-v. “yi” is a typical Ukrainian sound – it is combination of two Dutch/German sounds “j” and “i”.
So properly in Dutch/German that would sound like Kyjiv (The analogue in English would be Kyyiv, but they shortened it to Kyiv).
In Cyrillic it is written as Київ (or ~KUÏB~ in case your computer doesn’t support Cyrillic fonts).
It is not that complicated in the end of the day, is it?