Extract XYZ should work but does not provide the filtering and thinning that you desire. You would end up with all umpteen gajillion points, when what you really want to do is thin the number of points to a managable size.
My experience with the LIDAR tools are limited so there might be a better way, but here is what I would do:
Robert GarrettSenior Product EngineerBentley Systems Inc.
Neil Wilson (aka Neilw)
Power Civil v8i 08.11.07.245
AutoCAD Civil 3D 2018