Hyundai and Kia belong to the same group, which is similar to the relationship between Volkswagen and Skoda. The modern positioning is slightly higher than that of Kia, but there is little difference. All their cars are "compatible", and the places they can see are different (the exterior of the brand) and the things they can't see are all the same.
However, these two companies belong to two unrelated joint ventures in China, Beijing.