you can use DocumentQuery and filter based on the page type and country value of the parent pages.
Check if the Path or Where method is enough for your needs:
https://docs.xperience.io/custom-development/working-with-pages-in-the-api/reference-documentquery-methods
Or check the Where condition methods in this document and use the appropriate one.
http://devnet.kentico.com/docs/13_0/api/html/Methods_T_CMS_DocumentEngine_DocumentQuery.htm