adds helper to fix links to commentable

app/helpers/comments_helper.rb

@@ -20,6 +20,14 @@ module CommentsHelper
     end
   end
 
+  def commentable_path(comment)
+    if comment.commentable_type == "Budget::Investment"
+      budget_investment_path(comment.commentable.budget_id, comment.commentable)
+    else
+      comment.commentable
+    end
+  end
+
   def user_level_class(comment)
     if comment.as_administrator?
       "is-admin"

app/views/comments/show.html.erb

@@ -1,6 +1,6 @@
 <div class="row">
   <div class="small-12 column margin-top">
-    <%= link_to @comment.commentable, class: "back" do %>
+    <%= link_to commentable_path(@comment), class: "back" do %>
       <span class="icon-angle-left"></span>
       <%= t("comments.show.return_to_commentable") + @comment.commentable.title %>
     <% end %>