I'm having issues with getting segments to work within GA. When I set a condition segment for urls that start with a particular country/language extension it pulls in other country language urls. I've tried multiple variants of the segments and nothing seems to work (even when i use 'exactly matches'). These have worked in the past so i'm not sure what's causing this.
If you create an advanced segment and set the condition to e.g. "Include Sessions" where "Page Path" begins with e.g. "/en-us", then this simply includes sessions that had pageviews on pages beginning with "/en-us". If any of those sessions also viewed pages with other languages, e.g. "/fr-fr", then those will also show up.
Alternatively, you should create a custom report and set the filter to "Page" matches regex "^/en-us" or setup a separate view just for specific country pages using the same filter.