Configuring Multiple Selection
The Combobox can be configured to allow multiple selection.
Check the Enable Multi-Select box under Basic Settings :
Selecting items at runtime
A checkbox appears in front of every item, allowing multiple selection :
In addition, a new selection item called “Select All” (or “Unselect All”) is added at the top, to allow to select/unselect all items at once.
Clearing item selection at runtime
When Multiple Selection is configured, the Combobox contains a text box that allows the user to search for items
This search filters the content of the Commbobox incrementally and can be cleared using the cross button inside :