Hello Opigno forum, It's about the characteristic opigno main navigation menu with the big icons on the left. I would like to make sub-menues for it depending on what you click on it. As an example I would like a mathematics course button on the main navigation menu to lead to the same type of sub-menu with only mathematics related icons. I tried to make a new menu and connect it to the main navigation menu through path in edit menu link but I only receive an error message telling me the path name is invalid when I do it. Is there any way to make a navigational main menu in Opigno with sub-menues without making a lot of change in the code?