If you use the standard system “owner” function, you will only have 1.
For your requirement I would recommend setting an 1 to * association to the user. This way you will be able to set objects to multiple accounts and able to filter on it as well
hope this helps :)
It is not possible to have two system owners for Single entity,
But we can associate multiple users(Accounts) for that entity.
Account *------1 employee.
By using this association multiple accounts can access employee info.
I hope it helps you.