By default, Roof that are over the cut plane and below the top range of a View should display their exterior edges on Overhand (or hidden) line style.
You can archive this this with line work, picking one edge of the roof at a time, after applying and underline or changing the view's primary range "top". But thats is a time consuming task.
At least in my country, in architectural plans the overhang of roofs are almost always projected.
Other categories actually do this, for example Casework (you can see wall cabinet projected on hidden line style); but roof category don't allow that behavior.
https://knowledge.autodesk.com/support/revit-products/learn-explore/caas/CloudHelp/cloudhelp/2015/EN...
https://knowledge.autodesk.com/support/revit-products/learn-explore/caas/CloudHelp/cloudhelp/2018/EN...