Novel functionality in condensed matter physics is one of fastest developing fields, aiming for possible future applications including quantum computing, electronic devices and so on, leading to continuous discoveries of new materials and phenomena. This is part of these efforts in our research project to explore the novel functionality in quantum magnets. Here we propose to investigate a newly synthesized honeycomb-based multiferroic candidate with neutron diffractions to determine magnetic structures in successive magnetic transitions. We aim to understand the role of magnetic structures with emerging complex polarisations, hoping to have good ideas for designing new functional multiferroic materials and applications.