It can't record the info used by the dialogs unfortunately. But luckily they give us the workable alternative which is to first create a graphic style that has your offset path. Once this style is inside the document (you can auto-open a document and paste a style-applied shape from it into your work document), you can record an action that instead of activating a dialog would actually apply your named graphic style. Expand the style just like normal and your circle will shrink. Then, repeat (via the action or script)!