I generally recommend you not do that. Just move the contents of /home to the new, presumably bigger, disk and mount it on /home.
If you insist, and if it’s only one domain, you could bind mount it into home.
If you aren’t using suexec (e.g. FPM for PHP or other app servers for other language apps), you can put homes anywhere you want…but, from a maintenance perspective, it’s nice to have them all in one place. Virtualmin does not (and will not, because we want you to be happy and make good decisions) make it very easy to split up homes into a bunch of different places.