Certain type of layer problem described by the second order differential equations with the small parameter multiplying the highest derivative will be considered. The solution inside the layer, as well as the solution out of the layer, will be approximated by two different truncated orthogonal series. The character of the layer and the degree of the spectral approximation of the inner solution will determine the domain decomposition, constructed by the use of the appropriate resemblance function. Numerical results will be compared to those obtained earlier by the author, where the reduced solution was used to approximate the exact solution out of the layer.