Gui dropdown select many items

Question on GUI : is that possible to make a dropdown items, so you can select many items (not only 1 per time)

if there is no way to do it, is it possible to use toggles on a scrollview? if its yes, show me please.

why i ask this, i want to make items as much as my human bones got, so when i check an item then i can manipulate with my 3 slides (X Y Z axis).