In this work, we demonstrate a concept for the selective exciton-polariton ground-state (GS) condensation of a multilevel confined polariton system based on the Landau-Zener-like periodic energy modulation enabled by the GHz-frequency bulk acoustic wave (BAW). For large BAW amplitudes, the reservoir undergoes periodic adiabatic avoided crossings through all of the confined levels. Close to the resonance with the levels, the transfer from the reservoir becomes governed by the Rabi-dynamics, which can lead to the predominant occupation of the GS. We studied time-dynamics, which show pulsed coherent emission from the GS polariton condensate.