Choice Selectors
Default Selection
Choice Selectors can be empty or pre-selected by default.

Alternative for Multi-Selection
Currently, multi-selection is not possible with Choice Selectors, but an alternative could be a Group with Checkboxes.

Chained Choice Selectors
The options Group can be dynamically changed based on the selection of another Choice Group. For this, the chained Choice Selectors need to live in the same Group.
Formulas
Lastly, Choice Selectors can be used in Formulas.