You select Convert to Sheet Metal and select a face as neutral/base face. Then the edges that are supposed to be bend (pink). When you are done SW finds the Rib Edges (purple). Done.
When you select Flatten you will have a flat pattern.
You might want to change some parameters like radius, thickness, gap etc. I had to reduce radius to make it fold the relative short faces at the top.
Thank you Thomas for the prompt reply. Appreciate it.
To Add to Thomas and Deepak, You don't need to perform the delete face operation.
Just go in "Convert to sheet metal" command.
Select to bottom face as Base.
Select the required edge.