Do Stars in Galaxies also move in elliptical orbits? There is a gravitational force between every pair of objects, because of which planets revolve around the Sun in elliptical orbits.

My question is this: As planets move in elliptical orbits with the Sun at a focus so do the stars in galaxies also orbit, and if then what are the foci of their orbits. Since the gravity of black holes is very high are black holes at any of the focus of a star's orbit?
Planets orbit the sun in approximately elliptical orbits. The orbits of the planets are perturbed by each other, particularly by Jupiter. So the shape of orbits are very nearly, but not exactly elliptical. 

A simple elliptical orbit is found when there is a single dominating mass, for example in the solar system the Sun is much more massive than the rest of the solar system put together.

Stars in galaxies do move. However, they don't move in simple elliptic orbits for the simple reason that the mass of a galaxy is not concetrated at a single point. There is a supermassive black hole at the centre of the galaxy, but although it is massive, its mass is dwarfed by the mass of the rest of the galaxy (it has a mass of about 4 million suns, the galaxy has a mass of 600000 million suns.) The stars move in orbits around the centre of mass of the galaxy, to which the black hole contributes only a very small amount. The shape of the orbit is a "wavy circle". It is not elliptical, and so doesn't have foci.