Well, I can give you a few steps here. You can’t sort by nanite natively (you can with custom filters) but you CAN get all static meshes in your project or any folders.
Then you can use CTRL+A to highlight all, or select which ones you want specifically, and mass enable or disable Nanite use.
Now as for a custom filter- I am going to give you the page where I figured this out and you can try to use it to build your filter yourself, as a learning tool and to learn how to do custom filters yourself! That being said, if you would rather me just tell you the answer just let me know and I’ll post it. 
I try to give people the tools to their success instead of just doing it for them when it’s doable.