Here’s how to do a Multi-select Picklist:
{<br> id : 'selecteddivs',<br><b> type : 'multipicklist',<br></b> label : 'Select message centers',<br><b> picklistEntries: [<br></b><b> { value: 'one', label: 'Message center One' },<br></b><b> { value: 'two', label: 'Message center Two' },<br></b><b> { value: 'three', label: 'Message center Three' }<br></b><b> ]<br></b>}