For the liquid quenched to the glass forming state, its dynamics becomes slow, associated with the emergence of heterogeneities in structure and motion. The microscopic transient relaxation of the supercooled liquid towards a new equilibrium after deep quenching still remains an open challenging issue. In this work, our recent studies on this issue through direct tracking particle motion of a dusty plasma liquid after quenching are briefly reviewed. The spatiotemporal evolutions of multi-scale dynamics on the multi-scale heterogeneous network with increasing waiting time, their self-similar power law scaling behaviour of the observed behaviours, are presented and discussed. With the suppressed thermal agitation after quenching, the structural memory of the multi-scale patchwork which only allows the slow strain energy release and cascading through structural rearrangement is the key for the slow power law relaxation with large fluctuations.