HI @mtsts,
It is a known issue that ComboBox will directly display the count of selected items if the item name is too long.
There is no OOTB way to make item names fully expand.
As a workaround, you could add a Label under the ComboBox with Text property as below to display all the selected items:
Concat(ComboBox.SelectedItems,Value,",")
Or, you could set the Tooltip property of the ComboBox as the same above formula, so that it will display full name when you hover your mouse cursor over the ComboBox.
