These should do the trick:
Element By Id is fairly old and I believe that all supported builds have it.
PolyCurve.ByGroupedCurves may not exist for you (guessing you’re in Dynamo for Revit 2.6 and Revit 2021), in which case you’ll need to use a GroupCurves method (Archi-Lab has a custom node for this, or you can utilize some Python or DesignScript which has been posted a few places on the forum) to group the curves into pairs before using a PolyCurve.ByJoinedCurves node.