Enabling VMware to use multiple monitors on a chromebook

1. Log in to your Chromebook.
2. Download and install the VMware Horizon Client Helper extension from the Chrome Web Store.
3. Open a browser window on your Chromebook and type chrome://flags in the URL bar.
4. Scroll down to Unified desktop mode and click Enable.
5. Click Restart Now to restart your Chromebook and make the change take effect.

The vmware app will need to be ran in full screen mode.

From VMware article https://docs.vmware.com/en/VMware-Horizon-Client-for-Chrome-OS/4.5/com.vmware.horizon.chrome-client-45-doc/GUID-43B99078-6726-415A-AD93-C2DEC46D8861.html