I have a dropdown and a list and three buttons ,on click of one button i want to bind dropdown text to the list,and with the help of other two buttons i want to move the binded text to the list to move up and down

I have a dropdown and a list  and three buttons ,on click of one button  i want to bind dropdown text to the list,and with the help of other  two buttons   i want to move the binded text to the list to move up and down. How can we do this please help