When I look at a tree I see no 'thatness,'  for to my way of thinking 'that' is simply a pronoun that stands for  'the other one from this'.
I cannot conceive of a 'thatness' and a 'thisness' - for the moment one swings the attention from this to that, or from  that to this - this becomes that and that becomes this.

Anyway to award the suffix '-ness' to an adjective to form a noun, or to append or attribute  a state or condition upon a pronoun [like 'that' or 'this'] is exactly the same as attributing 'You-ness' or 'Me-ness' to you and I - what is the point? The entitative uniqueness of form and behaviour of you and me needs no additional attributive states,  for we already exist as we are.   I already 'am what I am' and you already 'are what you are,'  and we are in no need of an additional, extra, bolt-on, dual-version of our already existing existential reality.

'Being' cannot wrest anything from oblivion because it doesn't exist to wrest anything from anything. It is only your own mind which you conceive of as wresting the observed tree from oblivion through the medium of your own looking at it. In fact there are millions of trees in the world that exist in areas that will probably never be seen by human eyes - but they still exist.  How do we know that they exist?  By trusting the logic of our own brains and making judgements based upon our experiential involvement with such things. The tree exists, but its being only exists in the sense that it exists as being a tree in the continuous present.