From LongJump Support Wiki
Arrows in the platform generally appear in pairs (Up-Down, Left-Right) and are used to manipulate platform elements - to move elements from column to column, and to shift the order of elements in a column list.
To manipulate fields using Arrow Buttons
Select an element and use the left or right arrow button to move the element to a different column.
- To select multiple elements from a list that are not adjacent, press and hold the CTRL key and click each element individually (CTRL-click)
- To select a series of adjacent elements, click an element at the beginning of a series, press and hold the SHIFT key, then click the last element in the series (SHIFT-click)
To change the order in which the elements appear, select an element and click the up or down arrow button to change the order.