Section is a default parameter in Revit, it even appears in the pipe report, but I can’t get it from Dynamo
What have you attempted?
I’m not familiar with how Sections are assigned to fittings and accessories (presumably they are junctions that could be associated with multiple Sections), so this method is only really valid for duct/pipe elements.
EDIT:
This link describes a method to assign sections to fittings based on the connected piping via the MEPover package.