By default Haiku (as former BeOS) is displaying a new window each time you navigate to a new folder.
However, you can decide to change this behavior in the Tracker preferences.
I don't know if someone is using the default setup -which is creating a new window each time you go into a new folder-, but I find it very annoying.
To change this, open in the Preferences the Tracker.
Then tick the "Single window navigation" and "Show navigator" :
Above is what you will now have, when you are in a directory :
If you want to go back to initial situation, untick the "Single window navigation" and "Show navigator" :
Now you will be back to original situation :
Do you use on your side the default setup, or have you change it ?
Let's share your preferences in the comment below.