In terms of striped hyena biomes, I would definitely give them access to the temperate biome. They live in woodlands in the Caucasus Mountains, and in a nature reserve in Lebanon, they live in dense woodlands of juniper, pine and oak. In a survey there, striped hyenas were the third most common carnivore (behind red fox and stone marten) and fourth most common mammal (with the addition of Indian crested porcupine) in the woods, of thirteen total species.
I'd even be tempted to give them access to the tropical biome as well - they live in the Western Ghats of India, an area of forest with high rainfall, and they also inhabit mangrove forests on the east coast of India.