Import txt folder feature will do these.
For a subfolder,
- Create a Section named by subfolder name and import all .txt files in this folder into this section.
- Create a Section Group named by subfolder name and create its subfolder in it.
For a txt file,
- Create a new page and import the txt file.
Specify a txt file folder to import
- Click "Import" tab -> "Folder" group -> "Txt Folder" button.
- Check a notebook in left section tree.
- Open and choose a .txt file folder, OneNote Batch will list the .txt files and folder tree which OneNote Batch will create.
- Click "Start" button to start import.
After create section group and section, import .txt files. Follow is the sample.