Metallic nanostructures can enhance light-matter interaction arising from the surface plasmonic resonances, which is highlight on optics for many applications. A tunable optical property can be induced by plasmonic resonance, leading to the significant electromagnetic field enhancement, as well as the position of the "hot spot" at a tiny nanogap. Analogue of the diffractive optics, an alternative method of multiscale cascaded field enhancement with a simple metallic nanostructure, double stacked nanocone (DSC), was proposed in the article. In detail, a tunable hybrid mode was achieved from the strong interference between a fundamental plasmonic cavity mode and a plasmonic gap mode. Furthermore, it led to a far-field optical response at a certain wavelength. The position of the hot spots can also be mounted on the top surface of the DSC nanostructure. Additionally, a technique of mask reconfiguration was developed to precisely fabricate the multiscale DSC nanostructure, which can benefit to construct the necessary three steps in the nanostructure. The experimental results also provide a substantial evidence to demonstrate the art-of-state of the multiscale cascaded field enhancement, as well as the technique of nanofabrication.