I pronounce all three basically the same! doo-nee-yuh, but the second syllable is really short. I subconsciously pronounce the second syllable longer when it’s spelled [name_f]Duniya[/name_f], but they’re meant to be the same 
It can also be pronounced more like doo-nee-YAH, with a long third syllable, but I’m using the Arabic pronunciation instead of the Hindi/Urdu one.
such a beautiful name 