By default, Thunar always shows full names for files, while Nautilus adds "..." to the end of the file, so they all look the same.
Can I somehow make Thunar behave like Nautilus?
Sorry, It seems Thunar does't have this functionality yet (I've exhaustively searched in Google and XFCE Documentation, there is no mentioning of this feature in official docs).
Thunar stores it's user configuration changes in
I suggest you using nautilus. You can install it with
Alternatively, You can request a feature in by going to XFCE forum to implement this or even you can help them by your coding skill, if you want.