Hello Peter,

Please find the below Python code done in Automated Action. 
And add these fields :
- Trigger : On update
- Trigger Fields : select the toggle button field
- Action To do : Execute Python Code
Where ‘x_selection_field’ is the field you want to update based on toggle button field.

Find Example in comment.

I hope this will help you.

Thanks & Regards,
Email: odoo@aktivsoftware.com
Skype: kalpeshmaheshwari