Transdual Within Nondual
The way this comes out for me is a moving target, always changing.
Right now, it comes out this way...
Nondual
When what is awakens to itsef as having no "I" anywhere, it also awakens to itself as the ground everything happens within and as. Everything is revealed as emptiness dancing.
This is the nondual awakening.
The content is the same - this body, this room, this awareness - but none of these have any inherent "I". It is just what is, as it is. And the whole "I" phenomena is seen as just a temporary belief in the thought "I", and placed on a segment of what is - either this human self or pure awareness itself.
This is the Absolute. It is Big Mind, Buddha Mind, Spirit.
Transdual
But it is not the whole story. It leaves out the differentiation and change in the world of form and phenomena. It leaves out F1-F8 in Ken Wilber's framework, physical matter through to nature- and deity-mysticism. It leaves out the wonderful world of content.
This is an area where there is always change, and where the whole universe is revealed - through modern science - as one single seamless process of evolution.
Exploring differenatiated content within its nondual context
Where the nondual is the realization of emptiness dancing, with no need for differentiatons, the transdual is the exploration of the world of form within the context of the nondual.
We know - from plain logic, intuition or immediate realization - that everything is emptiness dancing. And this gives us a context for exploring the world of form in an always more deeply transdual way.