So you only want to show your other field if 2 other fields don't have the same value? It won't be able to check for that. The conditions are checking user input against a static value. Example as follows.

Field: name
Operator: Equal To
Value: Tom

In the above the field would display if the name field is equal to the value of Tom. The below lets you condition against a static substitution.

Field: name
Operator: Equal To
Value: [cb_othername]

This will work, but it will only work in display. It will not work in profile edit or registration because CB Conditional will have conditioned against the exist value of cb_othername. It can not live-update that condition during registration and profile edit.

There maybe a better way handle your condition. What are you trying to do exactly? What is the goal of this condition checking if 2 fields have same value?

Unfortunately there's no way to do that as CB Conditional doesn't support comparing a live edited field value against another live edited field value. It can only compare live field value against a static value. The usecase is so incredibly limited so it was never implemented as it'd be a lot of additional JS overhead. Best I can suggest is a checkbox field asking if they've a different last name and if they do display your second lastname field and a file field. Example as follows.

Field 1: Name
Field 2: Does the name on your passport differ from the name above?
Field 3: (if Field 2 = 1) Passport Name
Field 4: (if Field 2 = 1) Name Verification

I don't recommend doing that. You're complicating a simple setup. Use the above recommended setup and make Field 3 and Field 4 required, which are conditionally made visible based off Field 2 so they can be marked required. Users shouldn't need to supply their last name twice unless it's actually different.