
There isn't an easy way to handle that in a text file, nor will it be neatly represented if you did. The reason why you need an editor to handle dialogue trees instead of have it all in a text file matters when you have decision points in your dialogue. You should then simply be able to plug the translated file into your game, and have the game read off the translated text without issue. If you have your dialogue in text files, it is easy to send it to a translator who doesn't need to know what your game is like or context of the dialogue, but still be able to do their job and give you a translated version of your text. That requires another system altogether, but needs to work together with whatever you use to display text on the screen. The only reason I can see to store your dialogue in a text file is if you want to handle localization. At that point your dialogue can simply be stored in the scriptable objects.

The nodes will probably be scriptable objects in data form, but is essentially a string array in a scriptablt object. Having an editor tool to handle the creation of your dialogue trees will do wonders for your development time, especially if it's a node based system for your editor.
