Here are some steps to consider when create a nested ESXi Host. These steps are done on a vSphere webclient.

First adjust your security  on your switch so the traffic can pass through your nested ESXi host

vSwitch:
Select your host and click on the manage tab. Go to the networking section and select virtual switch. Edit the switch and select your security settings. Make sure your promiscuous mode is on accepted

nested_esxi_6_vswitch_security_settings

 DvSwitch:
Go to Home -> networking. Select your PortGroup and navigate to manage – Settings tab. Click on the edit button and select the security section. Make sure your promiscuous mode is on accepted

nested_esxi_6_dvswitch_security_settings

Now create a new Virtual Machine to run your new ESXi host in. Go through the steps like any other VM but make sure you chose

Compatible with : ESXi 6.0 and later

nested_esxi_6_compatible with

“Select OS family : Other” and “Guest OS version: VMware ESXi 6.x”

nested_esxi_6_select_guest_OS

Ignore the warning for now.

Make sure you have a minimum of 2CPU and 8GB of ram, Select “Expose hardware assisted virtualization to the guest OS”

nested_esxi_6_expose_hardware_virtualization

Select a hard disk of 8GB and set disk provisioning on “Thin”

nested_esxi_6_datastore

Add more networks if needed.

Now you can install ESXi like you would on a physical host. After its finished just configure your TCP/IP settings, DNS and time server settings and add the host to your vSphere. You can now also add it to a cluster without editing the CPU mask settings.

If you want me to make a video of this just leave a comment then.