Having a 9 star system is trivially easy, say, Star 1+2 orbit each other, Star 3 orbits the barycenter of 1+2, and 1+2+3 orbit 4, which is orbited by a pair 5+6, and star 7 also orbits 4, and star 8+9 orbit this entire system's barycenter. For an eight star system, you could have some sort of nesting with 4 binary pairs, where 1+2 and 3+4 orbit each other, and 5+6 and 7+8 orbit each other, and all eight stars orbit the common barycenter of the system.