How do I set the directory where ZIP files extract to?

I see that DO will view inside of a zip file.

I can extract a zip file. What's unclear is how to I set where I want it to extract to? Usually I want the zip file to open directly into the folder I've placed it in.

Depends how you are extracting it.

The easiest way is to simply right-click the zip file and choose the menu item that extracts it to the current folder. (Assuming you have Opus's zip context menu enabled in Preferences.)

You can also create a toolbar button (or hotkey etc.) to do the same thing to the selected zip(s) if you wish.