OptionGroup Widget: is Multiselection possible?

Plone Support Add-on Development
1

Hi,
i use the z3c.formwidget.optgroup in a custom Form in a Plone5 Site. Anyone know how to use this AddOn with the option "multiple" for the select list or is there another solution available?

2

Maybe http://docs.plone.org/develop/plone/forms/schemas.html#multi-choice-example is helpful?

3

Perfect, Thanks you saved my day!