We will discuss in the team the possibility of adding such an option and maybe we will add it.

Well, then a method needs to be added to the sidenav component to programatically open / close / toggle submenu items.

Unfortunately there is no method that would allow this. You need to set styles to rotate the icon 180 degrees.

When I say "programatically" it mean using Javascript. I have created a snippet so you can understand what I am trying to do. The submenu does open when I add the "show" class programatically, but the arrow is now facing the wrong way.

https://mdbootstrap.com/snippets/standard/marvin_herbold/3164293

You misunderstand my question. I am not talking about showing / hiding the sidenav itself. I am talking about showing / hiding a sidenav menu item that has sub-menu items.

For example, in your snippet, how would you open / close the "Category 1" menu item programatically?

Programmatically you could use method show(). See below snippet where I implemented simple event listener on a button which shows the sidenav. https://mdbootstrap.com/snippets/standard/m-duszak/3152956#js-tab-view

Other way you could use a button element which targets the sidenav with attributes. Where data-mdb-toggle="sidenav" is neccessary for every sidenav, and data-mdb-target takes selector of an element which you would like to show. https://mdbootstrap.com/snippets/standard/m-duszak/3153003

<button
  data-mdb-toggle="sidenav"
  data-mdb-target="#sidenav-1"
  class="btn btn-primary"
>
</button>