I had to create a vROps custom group of VMs based on port group connectivity information but was not able to do it with vSS(vSphere Standard Switch).
Because vROps supports objects, metrics, relationships for vDS only and not for vSS, I tried to use vSphere Tags as a workaround.
After create tag category > create tags of each port group names > assigned tags to VMs in vCenter,
I was able to create vROps custom group by vSS port group connectivity.
p.s. PowerCLI script which automates vCenter-side steps of this workaround was attached