We demonstrate the emergence of self-organized structures in the course of the relaxation of an initially excited, dissipative, and finite chain of interacting particles in a periodic potential towards its many particle equilibrium configuration. Specifically, we observe a transition from an in phase correlated motion via phase randomized oscillations towards oscillations with a phase difference π between adjacent particles thereby yielding the growth of long time transient spatiotemporal oscillation patterns. Parameter modifications allow for designing these patterns, including steady states and even states that combine in phase and correlated out of phase oscillations along the chain. The complex relaxation dynamics is based on finite size effects together with an evolution running from the nonlinear to the linear regime, thereby providing a highly unbalanced population of the center-of-mass and relative motion.