You can do something like that under Theme > Common (or Desktop, or Mobile, it’s your choise) > Body
<script>
Discourse.ExternalNavItem = Discourse.NavItem.extend({
href : function() {
return this.get('href');
}.property('href')
});
I18n.translations.en.js.filters.solved = { title: "Solved", help: "topics with solution" };
I18n.translations.en.js.filters.unsolved = { title: "Unsolved", help: "topics without solution" };
Discourse.NavItem.reopenClass({
buildList : function(category, args) {
var list = this._super(category, args);
if(!category) {
list.push(Discourse.ExternalNavItem.create({href: 'http://your-domain-url/?solved=yes', name: 'solved'}));
list.push(Discourse.ExternalNavItem.create({href: 'http://your-domain-url/?solved=no', name: 'unsolved'}));
}
return list;
}
});
</script>
In this way you add the buttons Solved and Unsolved on your menu.
You need only to change the URLs with your domain (and customize with a particular category if you want, eg http://your-domain-url/c/support?solved=yes)