Command called Create a sketch from selected elements creates Sketch from selected segments. Especially in my opinion, this is useful during 2D to 3D conversion.

Create a sketch from selected elements during 2D to 3D conversion

But today I will show the difference between this command and the Operation Convert Elements.

Converting You must first be in an active sketch, secondly, the projected sketch is whole.

Choosing in turn Create a sketch from selected elements You don't have to turn on the sketch before. You can also determine, which fragments of the sketch you want to transfer to the new one.

It is best to mark the wall/plane and with Ctrl selected segments of the visible sketch.

Unfortunately, an additional activity is to show the sketch, Because the sketch used in the operation is absorbed and hidden.