Get Repetition can return a specific repetition of the field.
But for button labels, you don't really need the calculation field.
You can simply place the field on top of the button and use the inspector to specify which repetition to display. When I use a data field as a button label, I usualy ungroup the button to detach it from any button setup option, then select the field and the button object before using Button Setup... to turn it into a button. That action groups the field with the button image while assigning it a button option.
Thanks for you reaction!
The thing I want is that the labels shown in the repetition field are based on the Privileges someone has.
Role ADMINISTRATOR: Home | Invoices | Customers etc
Role USER: Home | Customers etc etc.
That's why I want to use a calculation field. And not to make more fields in the table then necessary I wanted to use a repetitive one.
Then the GetRepetition function will allow you to define a calculation field that selects from different repetitions. You could also put the button label data in a related table and use a relationship based on your privilege set to return different labels for different users.