How to change Jupyter notebook's name (not the project's name) within Watson Studio project?

The (i) icon on the top right corner of the notebook only allows me to change the project's name not the notebook's name.

The following is based on the current UI in dataplatform.cloud.ibm.com as of 2022-11-10, and works similarly in recent releases of the on-prem version (Cloud Pak for Data).

To change the name of a notebook:

1. Open the notebook for editing.
2. Click the (i) icon near the top right corner.
3. In the panel that appears on the right-hand side, make sure that the "General" tab is selected.
4. Click the pencil icon next to "Notebook".
5. Edit the name and click "Save".

Next time you navigate to the list of notebooks, you'll see the new name there.

To change the name of the project:

1. Navigate to Manage -> General.
2. Click the pencil icon of the "Details" widget.
3. In the dialog that appears, edit the name and/or description of the project.
4. Click "Save".

Note that the name of the notebook has no effect on the filenames that you'll see when you export a project. Those cannot be changed. When you create a notebook, the filename is chosen based on the initial name of the notebook. If you are concerned about filenames, you can create a copy of a renamed notebook, then delete the original. The filename of the copy should then be based on the initial name of the copy.