Help with chamfer surface

Hello there,

I’m struggling to chamfer a solid with different distances from the edge (I uploaded a pic so you can see what I mean).
So when I use the chamfersrf command there a distance box with the values 1.00,1.00 but I can’t change them. As soon as I write in a different value it drops me out of the command?
Can anybody help me knows how to deal with that?

Thanks in advance,
Stefan

Uploading a 3dm file is always helpful in getting an response here. It’s just easier for people here to take a look at the file than to to infer from the screenshot.