Surface corner fillet

Does someone knows how to blend a corner from a surface? with polylines it’s possible. Looking for sth. like the fillet command for surfaces. Watch the attatchment, left is the base, right should be the result. Thanks for your feedback!

Maybe there’s a faster way I can’t thin of right now, but this method will always work…
Untrim, BlendCrv, CrvBoolean, Trim

i want directly blend it because the elements are not flat on ground, they have different directions…

Are the surfaces planar?
If so I would go for DupFaceBorder, Fillet, PlanarSrf and delete the original surface. Perhaps set up a macro with that.

One way

_ExtrudeSrf to solid

_BlendEdge or _FilletEdge

_Explode solid and delete unwanted surfaces or _ExtractSrf and delete solid