Magnetic planar nanostructures composed of ferromagnetic and heavy metals are a subject of intensive studies during the last years. Here we apply the technique of optical second harmonic generation (SHG) to the studies of planar nanostructures based on such materials, where the high sensitivity of the SHG probe to the spatial and temporal symmetry breaking is of principal importance. Based on the analysis of the SHG magnetic field dependencies, we show a clear difference of the magnetic behavior of the interfaces and of bulky materials, as well as additional features attributed to specific interfacial chiral magnetization distributions.