If I understand the question correctly, I think that this should not be done in the first place.
Two way binding is exactly what its name says. A binding that goes in two directions. A property value comes from the parent data, so if you bind to it, since it is a two way binding, while changing the bound input value you are actually trying to mutate the parent data variable which, as said in this post is done with events ($emit option).
You are able to do this for data variables because, I assume, you have the data object defined on the component as a local state.
yeah you assumed correctly
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