How to do: semicircle in the corner

Here is my problem

I need rise this the corner in walls and do is rounded off and it had the same shape.
When I try to lift with functions move, this are pulling me even at that wall.
How I can move with objects, without move objects near that?

Can you post an image so we can understand better.

Oops didn’t see the link.

The model would make it easier to answer.

I need do similar to this

I’m having trouble seeing the relationship between the two pictures you posted. Please try again to describe what you are trying to accomplish?

Regarding the question in your first post, SketchUp always “sticks together” any primitive geometry (edges and faces) that shares vertices. If you move one such entity, the others are dragged along. The only way to prevent this is to gather some part of the geometry into a group or component.

you have to draw the profile right the first time then use the follow-me tool.

if you want the hip to be created using different profiles as shown in your first picture:

use push-pull to extend both past their intersecting point:

select the geometry then right-click → Intersect faces with selection …delete the unneeded parts: