Another alternative to @sublimeartistry 's suggestion above would be to export the view(s) you need as an svg via file->export, then use a svg editor such as Inkscape to add the dotted lines. It is a little messy (you would need to redo the export and re edit the svg if you change the sketch) but it should work, but if it works for you , @sublimeartistry 's suggestion is better as it is in the sketch with no post processing required.
Peter