There was a plugin that expanded the line to the desired extent. But I don’t remember. Is there anyone who knows this plugin?
Adebeo Push Line: https://extensions.sketchup.com/en/content/adebeo_pushline
If the original edges aren’t collinear you can use the native Offset tool. If they are collinear (or just a single edge) this tool can’t be used as there is no defined plane for it to work in.