There are four species of hyena: the spotted hyena, the striped hyena, the brown hyena, and the aardwolf. All of them appear vaguely doglike, but none of them are that closely related to dogs.
They hyenas closest relatives are civets and genets. In fact, the primitive looking aardwolf, which lives largely on termites, was once thought to be a species of civet. The civets and genets, the mongooses (including the meerkat), the carnivorous genet and mongooselike animals of Madagascar, the African palm civets, and the cats all represent the Feliform suborder to the larger order Carnivora. The hyenas are in this group, which represents this evolutionary relationship.
The other suborder is the Caniform suborder. In this suborder are dogs, bears, the red panda, skunks and stink badgers, the weasels (including mink, otters, badgers, ferrets, the fisher and marten species, and the wolverine), raccoons (which includes the ringtail, the coati, and the kinkajou), and the pinniped species, the eared seals, the true seals, and the walrus. (Pinnipeds are often considered in their own order, but the consensus is that they are part of Carnivora.)
Both of these suborders represent the evolutionary relationship between the members of this order. Some these families have been split over time. Once skunks were considered part of the weasel family, but now, they and the Southeast Asian stink badgers are classified together. The red panda has been classified as a bear and raccoon, but now it is included in its own family. It is believed to more closely related to weasel and skunk families than to the bear and raccoon family.