To retrieve the latest version of a page (or master, etc.) from the shared project directory, you can update the page. To update a page, right click on the page in the Sitemap pane and select Get Changes. Some project properties may also be updated when updating a page.
It is good practice to update your copy of the shared project frequently to keep it up to date with the shared project. You can do this using Share->Get All Changes from Shared Directory.
To update multiple pages to the latest revisions, select the pages in the Sitemap, right click and select Get Changes.