In the state of Wisconsin, is there anything that states a POA has a right to say who and if the person can leave the facility?

What type of facility? Assisted Living it Long-term care?

Are you the PoA wanting to know? Or are you the person who wants to take the elder somewhere and the PoA (who is not you) is saying NO to you doing this?

I don’t think you know what the acronym PoS means

Do you mean the POA or power of attorney?
Because when you go into care you will be assessed by your own admitting doctor from a rehab or a SNF or hospital or just your OWN doctor. THAT person will fill out forms saying whether you can leave the facility safely unaccompanied in almost all cases.

I would discuss this with the administration at the facility.