Create WordPress function that allows pages to act as directories and sub-directories and locate pages and posts within them.

Please read detailed PDF brief for the full specification of this project. A short overview of the project is outlined below: 1. Create a new option panel shown on the left of all Pages and Posts which: A. Allow pages to be used as directories and subdirectories i.e. shows a selected page using this structure in XML Sitemap, Browser, Permalinks etc. B. Allows selected pages and posts to be located in these directories and subdirectories. C. Allows selected posts and pages to be located in these directories and subdirectories to also be viewed in other places i.e. other additional (potentially multiple places) directories and subdirectories. But to specify one place that will be used as the primary location – for the purpose of the XML Sitemap and Permalink. D. Allow duplicate Slug values to be created for pages, as long as they are located in separate/different directories and subdirectories etc. (similar to how Page Attributes work). 2. Update an existing function php code (see sample in PDF) that creates a ‘Shortcode’ for (next and previous) posts matching certain criteria, so that they always run in the correct directory/subdirectory where they are located, or they are all forced to run in the same directory/subdirectory that has been requested in the URL input into the web browser.