Numerical modeling of boiling flow is challenging due to the wide range of characteristic lengths of the physics at play: from nano/micrometers bubble nuclei to sub meters' flow pattern, particularly, when the role of the nano/micro surface structure attracts more attention recently. To address this, we present here a multiscale approach concept that smoothly bridges the Molecular Dynamics (MD) simulation of bubble static/dynamics wetting, the Direct Numerical Simulation (DNS) of bubble dynamics considering detailed surface structure, the Euler Euler (EE) of boiling flow considering the bubble void fraction distribution and GEneralized TwO Phase flow (GENTOP) model to simulate the large free surface structure. The approach is demonstrated on several problems including the contact line region of a nucleation bubble, microlayer beneath the bubble, bubble dynamics on a surface, bubble population balance, interfacial forces between dispersed phases, and free surface. These examples highlight the capabilities of the developed multiscale model in simulating boiling flow with various pipe/channel designs and structured surfaces.