In discussing the One of Plotinus, Dominic J. O'Meara writes the following (page 46):
Plotinus points to a distinction between elements which exist only as components of a whole (they depend on their status as parts of a whole in order to exist) and elements which make up a whole, existing both as parts of the whole and as independent of the whole. It is the latter type of element that is relevant to the Principle of Prior Simplicity. This element leads a double life, both in a whole, as part of it, and outside the whole, as in itself.
For example, for Plotinus the soul "is both part of (in) the world and separate from it".
O'Meara continues:
This is no universe where immanence excludes transcendence. Plotinus would not accept a view that would force us to choose between a god that is part of the world and a god that is separate from it: god is both.
O'Meara cites the Enneads V. 6. 3. 10-15 and V. 4[7]. 1. 5-15.
Does this view of God being both immanent and transcendent originate with Plotinus?
Reference
O'Meara, D. J. (1995). Plotinus: an introduction to the Enneads. Oxford University Press.