The URL is relative to the location of the CSS file, so this should work for you:
url('../../images/image.jpg')
The relative URL goes two folders back, and then to the images
folder - it should work for both cases, as long as the structure is the same.
From https://www.w3.org/TR/CSS1/#url:
Partial URLs are interpreted relative to the source of the style sheet, not relative to the document