To get the full benefits and support of the new vSAN 8 Express Storage Architecture (ESA), you will need modern hardware from the official vSAN ESA Ready Node HCL. However, from an education and learning point of view, you may want to explore some of the VSAN ESA workflows and easiest way to do that, well you probably know the answer .... it is using Nested ESXi of course!

With my recently published vSphere and vSAN 8 Lab Deployment Script, you can use that as the base and the Nested ESXi 8.0 IA Virtual Appliance to setup vSAN 8 ESA using virtual hardware 

Once you reach the end of the wizard, you will be presented with a summary and enablement of vSAN ESA will begin.

Again, this is purely for educational and learning purposes, especially in familiarizing yourself with the vSAN ESA enablement workflow. Outside of the initial workflow, I am not sure there will be any real benefits of using vSAN ESA in a Nested ESXi environment, especially compared to the vSAN Original Storage Architecture (OSA) which can be enabled with just 8GB of memory per host versus the 16GB required by vSAN ESA.