I'm making a building that uses its submenus(2,3,4) to train units. However, everytime i train a unit the command card always bring me back to submenu 1. Is there a way to fix this?

In Data editor:
Press ctrl + D to swap to the raw data view and disable "Combine Structure Values".
Go to Units tab and select your unit.

On the right side there is a field like this:
CUnit_CardLayouts_LayoutButtons_SubmenuIsSticky ((0|0|0|0|0))

You can make them stay open after usage with swapping the 0 with the 1 for the corresponding command card number.

I think that was it.
The field isn't existing in all other views. So if a modify-window pops up, it's wrong.

I got it. Thanks