If you're referring to Windows vertical or horizontal window tiling, we don't support that with documents in SQL Developer. However, you can take your worksheets and create new tab groups. Just mouse-right on your worksheet tab and say 'New Document Tab Group.' You can repeat this as many times as you want.
You can also drag a Worksheet to get left/right or top/bottom worksheets so you can work on multiple documents/scripts simultaneously. Here's a quick example: