Button Group is a container of several buttons, where at each time exactly one is selected (compare with Selection Field).
By default, Button Group includes a single button named "Radio Button 1". To add additional buttons, right click Button Group and select Add Element -> Radio Button.
You can change a button's caption by setting a value to its <Caption> element (if no value is specified, the name of the button's element is used).
Initially, the first button is selected, or, if a value has been set to the <Value> element of the Button Group, the matching button is selected (i.e. the button whose caption is equalt to <Value>).
When a button is clicked:
Here is a screenshot of a page with a Button Group containing two buttons - "Native" and "Web" (model - Native Mobile App.tersus):
Selections.tersus uses both& Button Group and Selection Field to implement the same selection (in this particular case, Button Group seems to be a better fit):
For best results, use the Firefox browser..