Hey @Neeraj_27 this will require customization. So I would recommend making a clone of the OOTB widget ( topic_content) and leave the original intact.
If you look in the Server Script you can see how the Filtering is defined
function getFilterName(table) {
var content_table_filter_map = {
'sc_cat_item' : REQUESTS,
'kb_knowledge' : ARTICLES,
'sn_lc_course_item' : COURSES
};
return content_table_filter_map[table];
Your going to have to add new code (and corresponding code elsewhere) if you want to add filters returning this level of detail. Currently our filters OOTB simply break out between Requests and Articles.
It might be worth discussing what value this filtering option will bring, versus the technical debt you will take on having this custom widget (which you will need to ensure is on every topic, this is where you can use custom topics) and acknowledging your platform upgrades will skip over this core widget, as it is seen as customised.
Typically managing and/or restricting availability to users in X country is done through User Criteria on the Catalog Item or Knowledge Article itself. So might be worth reviewing why you need to implement customisation instead of using a longstanding OOTB feature
