The external and independent control of parallel and perpendicular flow shears in collisionless magnetized plasmas is realized using segmented plasma sources. Then, ion flow velocity shears parallel to the magnetic-field lines are observed to destabilize not only the drift-wave but also the ion-cyclotron instabilities depending on the sign of the parallel shear in the absence of field-aligned electron drift flow in laboratory experiments. On the other hand, perpendicular ion flow velocity shears are demonstrated to suppress both the drift-wave and the ion-cyclotron instabilities, and furthermore, the suppressions are found to take place independently of the sign of the perpendicular shear.