Field Option Source - Alekseon/magento2-widget-forms GitHub Wiki

Options Source is available only for fields with below input types:

• Dropdown
• Multiple Select

By default You can choose between:

• Default Attribute Options
• All Countries
• Website Allow Countries
• Yes/No

For developers, its possible to define custom option source: Custom Options Source

If Default Attribute Options is selected You can go to Advanced Settings to define Your own options.