端部のサーフェス作成のやり方について

I’m having trouble figuring out the workflow and commands needed to cover the end portion shown in the attached image with a surface.

I have tried using commands such as Sweep2, Loft, EdgeSrf, and BlendSrf, but I haven’t been able to achieve the desired result.

I would greatly appreciate any guidance or advice. Thank you in advance.

Try Patch. You have Rhino 8, you should try downloading the WIP 9.0 version. The patch command there will surprise you at how good it is.

The standard way to close a round-ish end-cap in NURBS surface modelling is this patch layout.