Existence of trigonometric and hyperbolic function solutions together yields complexiton solutions. This condition is the nature of complexitons, makes the process harder and provides them a different type of wave speed. Modified double sub-equation method is a useful and practical tool to obtain complexiton solutions of nonlinear partial differential equations. Employment of two wave transformations makes modified double sub-equation method more general than methods that use one wave transformation. These two wave transformations also provide trigonometric function solutions or hyperbolic function solutions. In this study, application of modified double sub-equation method for new form of (2 + 1)-dimensional BKP equation is given. Wave propagations of some resulting solutions are illustrated.