I have read the docs and I'm not clear on it. i followed search essentials and would like to use unions to search multiple columns. I have this right now in my post model:

 public function scopeSearch($query, $search)
    {
        return $query->where('title', 'LIKE', "%$search%");
    }

this is in my BlogController

public function index(Request $request)
    {
        $query = $request->get('q');

        $posts = $query
            ? Post::search($query)->paginate(15)
            : Post::paginate(15);

        $tag = $request->get('tag');
        $data = $this->dispatch(new BlogIndexData($tag));
        $layout = $tag ? Tag::layout($tag) : 'blog.layouts.index';

        return view($layout, $data)->withPosts($posts);
    }

This is what I want to do but don't know to make it work

	    SELECT title FROM posts
			WHERE title like "%$query%"
			UNION
			select subtitle from posts
			WHERE subtitle like "%$query%"
			union
			select title from tags
			WHERE title like "%$query%"
			union
			select subtitle from tags
			WHERE subtitle like "%$query%"

any help would be beyond great