Close vs. Exit (^X)

I am not very familiar with text editors.
Is there a way to "close" a opened text file in nano without exiting?
So far, I exit (^X) then re-enter with the nano command +filepath&name
to open.

When a file is open, I can open a new file in a buffer (multi-buffer) or
I can append the a new file in the existing one, but this is not what I
am looking for.

I would like to "Close" a file in nano (nano window is empty) and
directly ^R to open a new file.