Hi Johannes Hessellund,
Thank you for using Syncfusion controls.
We have not clear with your requirement. Can you provide the below details?
· Do you want a command action for ComboBox collection’s first item or first TreeGridComboBoxColumn cell value?
· When did you want to fire a command action?
It will be helpful for us to investigate further and provide you with a solution at the earliest.
Regards,
Susmitha s