Add a Select Dropdown to the default Sidebar which houses a checkbox form.

Was wondering if somehow I could get the default “checkbox” form in the sidebar to become a select dropdown form at “xs” small sizes. The default sidebar uses checkboxes in a form which works great and even disappears at small screen sizes but was hoping to append the drop down select form to appear at those small screen sizes then disappear at larger screen sizes to make room for the default “checkbox” form. Might need to get the sidebar options that are checkboxes to turn into a select drop down menu… maybe, not sure.. please any help would be great