Yes, you can easily access the website root with the help of Page object. You can directly call getAbsoluteParent method to access the root page at a level of your choice.
Code snippet for the component would look like:
Sightly HTML code snippet:
<div data-sly-use.contentJS="content.js">
${contentJS.parentPage.path}
</div>
Content.js
use(function() {
return {
parentPage: currentPage.getAbsoluteParent(1)
};
});