The elaborate complex consisted of two separate levels , the `` Vorbunker '' ( the upper bunker ) or `` forward bunker '' and the newer FÃ 1\/4 hrerbunker located one level below . The elaborate complex consisted of two separate levels , the Vorbunker ( the upper bunker ) or `` forward bunker '' and the newer FÃ 1\/4 hrerbunker located one level below .