At present, the actual task is to study magnetic microstructures, the characteristics of which can be controlled by changing static magnetic and electric fields. Thin films of yttriumiron garnet show much lower damping of spin waves in comparison with metallic magnetic films. The propagation length of spin waves in magnetic microwaveguides and magnonic crystals is of the order of a few millimeters at room temperature. The use of lateral magnetic microstructures is important for the development of interconnection elements in planar topologies of magnonic networks. The control of frequency tuning by means of a magnetic field for magnonic devices is slow and requires a large expenditure of energy. In contrast, electrical adjustment is much faster. In the present work, a numerical simulation of finite element based modeling has been performed to study the spatial dynamics of hybrid electromagnetic spin waves in a multiferroic heterostructure formed from parallel oriented ferromagnetic microwaves with a ferroelectric layer. The possibility of hybridization of the transverse modes of waves propagating in the ferroelectric layer with symmetric and antisymmetric modes of the lateral structure is shown, which makes it possible to transform the dispersion characteristics of a multiferroic structure with a change in the electric field applied to the ferroelectric layer. The effect of changing geometric parameters, such as the thickness of the ferroelectric layer, on the electrodynamic characteristics of waves in a heterostructure was studied. On the basis of the proposed lateral multiferroic structure, it is possible to create couplers and power dividers of spin-wave signals with a double control.