Reset data of option page

[valentinsld]

Hello !

I have created a option page with the snippet example and I would like to create a button to reset all fields with own values.

So my first question is : "How can I reset all fields (and repeatable groups) on a option page ?"
And the second is : "How can I set values for field (and repeatable group) on a option page ?" I know CMB2 have 'default' for each fields, but how it's work for repeatable group ?

I'm sorry if it's writed on doc, but I don't found it
I thank you in advance ✌️