If you use subdirectories with gTLDs (e.g.,
mydomain.com/ua/) to target site content to a specific country, you should place that content within the country specific subdirectory (e.g.,
According to Google, although it's strongly recommended to provide unique content to each group of users, it does understand if similar content appears in URL structures like the above that it recognizes, as listed under the "URL structures" and "Duplicate content and international sites" sections here: Google Webmaster Tools - Multi-regional and multilingual sites
Since all of this content is located on the same domain, any links between the subdirectories/countries and other directories would be considered internal links, not backlinks coming from external domains. There is an SEO benefit with internal links too however, as covered in that link. And each internal link found within your content and sitemaps(s), which can target multiple countries, will be crawled and indexed as well.