MultipleSelect get TextInput

[anaether]

Hello guys,
I need to know how i can access the current written text from from a multipleSelect. If you have only one you can use a KeyDownEvent. I have multiple of them and the KeyDownEvent fires but its always empty.
I get the input from the keyBoard but not the id from the control in which it has been written. So is the problem i dont know from which multipleSelect the input comes. Does someone know maybe a way how to do it?