Restricting VM Selecting While Running a Workflow?

When a user logs into the vSphere Web Client, they only see the VMs they have permissions on - this avoids a lot of confusion.

When the same user runs a workflow from the vCO Web Operator or Client, they are presented with the entire vCenter directory tree - asking a user to drill through 1,000 VMs is difficult.

Is there a way to limit the VC:VirtualMachine input to only the VMs the user as access to?

I've got a few Snapshot workflows, but the snapshot options that precede the workflows in the vSphere web client will no doubt create confusion. So I'm hoping to only educate users on the vCO Web Operator or Client. This is version 5.1.2

Thanks!