Here's a breakdown of the pronunciation:
* у (oo) - like the "oo" in "moon"
* би (bee) - like the "bee" in "bee"
* йств (ystv) - the "y" is soft, similar to the "y" in "yes". The "stv" sounds like the "st" in "stove" followed by a very short "v" sound.
* о (o) - like the "o" in "hot"
So, the full pronunciation is oo-bee-yst-vo.