A CMO represents an organization that helps with all things Change. Sometimes it might be called a Change Management Office (CMO) or Change Management Organizations (CMO) or Configuration Management Office (CMO), etc. Change also comes in a couple different favors: 1st Order Changes are know as continuous improvements and 2nd Order Changes are know as major step changes. Therefore, your CMO could also support your Lean Six Sigma efforts.
Likewise, a PMO represents an organization that helps with all things Projects. Sometimes it might be called a Project Management Office (PMO) or Program Management Office (PMO), or Project Management Organization (PMO), etc.
This is where you can find, training, templates, project managers/people, and other resources to help your organization.