Looking at a tree I see no thisness and thatness.  This and that are simply demonstrative pronouns which symbolically stand for the other one (or ones) or some some deitically pointed at object.

This; that; these; those; none and neither are demonstrative pronouns that substitute nouns when the nouns they replace can be understood from the context. They also indicate whether they are replacing singular or plural words and give the location of the object. Objects do not exist in states of being this or that and thisness and thatness are reifications which do not refer to any specificity or singularity.

The moment one swings the attention from this to that, or from that to this - this becomes that and that becomes this. Palpably objects are incapable of such transcendentalistic occult   change. Therefore thatness and thisness has nothing at all to do with the ontology of observed objects and everything to do with the childish vocabulary of the philosophical naif who makes such references.

In other words such words have everything to do with the Heideggerian nursery-like argot. The ideative baby-talk of the person concerned  with such utterances  has nothing at all to do with what he or she is looking at.

To append the suffix -ness to an adjective in order to form a noun, or to append or attribute a state or condition  or so-called state of affairs upon a pronoun like that or this] is  an act of reification - a departure from the real world of sensibility.  Attributing You-ness or Me-ness to  the personal pronouns you and I - is an act of semantic vandalism. What is the point with such inane transcendentalisms?

The material uniqueness of form and concrecity of the behaving you and me needs no additional attributive pseudo-states, for we already exist as we are. I already exist as I exist and you already exist as you exist, and we are in no need of an additional, counter-intuitive, ontologically different bolt-ons.

So called Being cannot wrest anything from  some transcendental oblivion because neither being nor oblivion exist to wrested or to wrest anything from anything. It is simply the idealistically imprinted brain which conceives of as wresting the observed tree from oblivion of the experiential continuity through the medium of looking at it - and looking does not exist either - only the looker and what is looked at exists. There are millions of trees in the world that exist in areas that will probably never be seen by human eyes - but we know they exist.

How do we Homo sapiens know that so-called noumena exist? By trusting the logic of our evolved brains which, packed  as they are with 100 billion neurons,  have experienced such an earthly environment since the appearance of Homo sapiens about half a million years ago.   We read reports, descriptions, listen to what travellers tell us,look at satellite photographs, study botany, forrestry and  topography.  We make informed judgements based upon our experiential involvement with such things.

The tree exists, but its thisness and thatness does not. Its so-called being does not exist either. The tree exists,  but the fact that it exists does not.  The tree exists in the sense that it exists in a form which humans call a tree.

When a tree dies, that from which it was constituted becomes part of the fabric of other entities - as does that which constituted the thinking brain-meat of the animal which calls it a tree.