Hi Ms851102,
To use split view in Excel for Mac, you can try the followings:
Put your cursor on the green button in the upper left corner of one workbook, left click and hold the green button for 2 or 3 seconds, you will see the window resizing, then you can drag the window
to the side you want. On the other side of the screen, open another workbook.
Here is an article for your reference:
macOS Sierra: Focus on apps in full screen or Split View
Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked
sites or any support related to technology.
If you cannot use the split view, please provide your Office version and Mac version for troubleshooting.
For Office version, you can check it via Excel menu in the upper left corner>About Excel.
For Mac version, check it via Apple menu>About This Mac.
For Visual Basic in Excel for Mac, please refer to this article:
Use the Developer tab to create or delete a macro in Excel 2016 for Mac
Regards,
Tina