How does one define OSX paths in Base?

I am trying to add links to images in a Form in BASE but I can’t find information on how the paths are structured in BASE with respect to OSX. Running under localhost I assumed the path starts from the root directory (user/sites/…)but this does not appear to be the case (or I’m overlooking something) for when I set a path to a directory and image file, nothing shows up in the Form in the Image Control window I’ve added (linked to the Image File name & path defined as “sub_d/file.jpg” without quotes). Tried putting that directory and file under all the /sites directories and sub-directories related to the database file with no success. Also tried under XAMPP/htdocs(/sub_d/file.jpg) section - no joy.
Using this page as a guide for linking to images, however the author uses MS path structures not OSX. Using XAMPP for running LOCALHOST.

Argh…well, that was easier than I thought. So, the structure is /Users/name/Sites/sub_d or wherever I placed the file. Localhost is ignored (at least for now). On to the next problem…