How to implement nosql CMS site structure in php?

Question

CMS

I have already written everything again 50 times, each time I did not like something in my pseudo-CMS. This time I faced such a problem:
The site is based on Joomla, it has all sorts of mods that are needed. The store page displays a blog of materials, in which an iframe is added referring to the "pseudo CMS" lying a little on a different path from joomla.

That is, the link to the material looks like this: domain.com/joomla/category/material < here iframe
It refers to the folder domain.com/shops/shop_name/index.php - which actually displays.

Initially, I used REQUEST_URI, which compares to the sitemap array and returns a link to the page's array. This approach does not work, because joomla CNC displays an address different from the location of the pseudo CMS.
Actually, that's the question, now I got the idea to use directories with index.php nested in it, database array.
That is, create a folder with two files each time (one will look for the root using while $base != '/' { $cd + "../";}) So that each page would return to the folder back and ask the database of this directory for the current location, if not the root, then exit another folder. When the path to the material is built, you can immediately display relative paths for menus, links to materials, products. I don’t know what pitfalls there are, and redoing it 500 more times is certainly good, for experience, but it takes a lot of time.

Thus, the page will be able to look for the place where the index.php lies, from which everything starts. Apparently all links on the page should be relative, not rigidly linked.

Tell me, what methods can be used to implement cms so that there are no problems with displaying through an iframe, so that the Joomla CNC does not interfere with moving inside the frame? do not judge strictly, I have not been developing in this direction for a long time, but I am learning and I will be grateful for any concepts that will bring me closer to implementation.