unreal engine merging same project

Hello everyone, we are a team of 4 student working on a motion design project.
we set the base 4 levels for each with master level gathering all 4 levels.
we are working separately, each one of us doing his part buy adding assets and animation.
we would like to merge the 4 projects that share the same name same set up same everything into one project file and keeping the position in their level and outliner.
Thank you so much…