Use the local file path box to specify where the resource files associated with the HTML document are to be placed. (Leave the box blank to place the associated files in the same location as the output HTML document.)
Specify the full path.
The associated files will be placed in "D:\MySite\Images" irrespective of the location of the HTML document.
Specify a relative path.
The associated files will be placed in a folder named "Images" in the location set up for the HTML document in the HTML export dialog.