Smooth curve from Autocad

Hi all,

Here i just imported the CAD aligmnent file into Revit and want to create a single polyline for both the lines (Magenta and blue) using dynamo but its not working well. Please give me solution for this one. Thank you
test.dyn (15.3 KB)

After you get curves, you can try PolyCurve.ByJoinedCurves node to combine them.

I tried but its not working. I want all the lines to be a single polyline

Is it possible for you to show your Dynamo graph by showing the result of each node?