form builder - control event not working with multi-select

I have got the same problem in form builder 2, event. image_2020_01_29T09_30_21_444Z

In my case, Aneurysm Site is multi-select & Side of each answer (A Com A Side, Vertebrobasilar, ICA Side, DACA Side, MCA Side, P Com A Side, PCA Side) will be hidden primarily & will be shown on click each answer of Aneurysm Site. I can get value by calling form.get(‘Aneurysm Site’).getValue() when Aneurysm Site is like radio & can’t get any value when Aneurysm Site is multi-select.

Please kindly help me on this case. How can I get multi-select field value from observation form in the event by calling form.get(‘Aneurysm Site’).getValue(). @angshuonline @binduak @ramashish