Abstract When reacted with ionic liquid [BMIM][BF 4 ], Ge monolayer networks (germanene) in Zintl‐phase CaGe 2 crystals transform into multilayer (bi‐ or tri‐layer) germanenes in CaGe 2 F X (0 ≤ X ≤ 1.8) compounds. The structures of these germanenes are discussed with the aid of high‐angle annular dark field scanning transmission electron microscopy (HAADF‐STEM) images. One of the bilayer germanenes is a new allotrope comprising four‐, five‐, and six‐membered Ge rings, which is of the same structure as previously reported bilayer silicene. The newly obtained structures of trilayer germanene are not of the cubic diamond type; however, they are described with combinations of hexagonal stacking, similar to the high‐pressure bulk phases. Their differences, as compared with multilayer silicene, suggest that the structures of multilayer germanene and silicene depend on the misfit between the layers of CaF 2 and Ge (Si). We anticipate that these results will contribute to the design of materials with attractive properties using tetrahedral coordination and/or by controlling the segregation and reconstruction of group‐IV elements.