You can pause the script indefinitely and then the user can take as long as they need, clicking continue to continue the script.A continue button appears in the tool bar area and you can also add your own continue button if you don't want tool bars to be visible.
You can simply record the current layout name or number in a global field or variable and simply end the script after bringing up the layout. A button on Layout 2 can use the layout name or number saved in this manner to return the user.
You can use new window to open a new window and take the user to layout 2. When the user is finished, they close the window to return.
You can set your pause script step to "Indefinite." Then, when you set up your button, set the control to "Resume Script."