Hi.
You would have to be more specific about your problem.
If what you are trying to achieve is working directly on a drawing placed in a layout (like working inside a viewport in cad), then you can't do it. Just select the drawing in layout, right-click and choose Open source view; this will open the view with its saved settings so you can make changes. Upon returning to the layout (and depending on drawings settings) it will be updated.
Cheers