Yes, hypermart is the best place to shop in Dumaguete. Worth stopping at WhyNot for the loaves of bread they sell too. Their cereal bread is the best bread in town. They have a small selection of other goods you're unlikely find anywhere else in town.
good grocery stores Might vary with different goods; Fortune Mart has many things others do not offer. And it is willing to stock wanted groceries. I do not know if there is anyone in other grocery stores with whom to talk about desired goods. FWIW There are several good stores in Bacolod. In Cebu Metro at Ayala is very good.
Check them all out, take a note of what is available and when it is time to shop build a list and make the rounds. Each of the stores has a imported section with some od the same items but some items unique to that store. The best foreign food section is not in dumaguete, but in my opinion can be found at Metro Markets in Cebu and Manila.
I usually take a big empty suitcase and go to Manila or Cebu. I did find sauerkraut at Fortune mart I could find nowhere else. along with tortillas small size wheat and flour.