Take down the topper you have now ,hang new curtain Rod higher and wider than the arch in the window, handg curtains on wither side of window but with enough fabric to cover the window if closed ,I suggest grommet panel type for ease of movement

If you are mainly interested in getting some drapery up there then you're best bet might be to raise the rod above the arch and have panels on either side. I would also suggest a panel for the middle which would make the window look a bit smaller then it is.

One option you might consider, depending on if you need privacy or light control, is to install stationary panels. Either on the sides or add a third in the middle column as suggested above. This gives you the option to add some color and/or texture to the wall space.

I like to put a rod across the last level place before the arch . . then hang panels on both sides of each windows that can be drawn together . . . since the windows are separated by a significant margin, better to "hide" this with drapery / softening elements, and this treats the arched elements as transoms, which also elevates the look. Place your rod across the highest "square" point (now top of shades, basically, or any element within the window framing that signals that point) . Extend the rod beyond the frame to the outside of the window at least 1/2 the width of the separation between them - when the panels are drawn open, the entire window assembly will look bigger and better. Neutral panels, try for 2x actual width so you have lots of fullness when open.

I agree. Window is big and nice lights so just on the top with wood and on each side longest treatment to can