Linked Glossary of Terms
(references to De Wijsbegeerte der Wetsidee, unless indicated. See concordance for correlation with pages in the New Critique. The concordance is in pdf format.)

One I, 134 (one in root)
unity I, 30 (in neo-Platonism), 40 (of cosmos), 44 (unity-identity), 57 (unity-totality), 60 (naive experience of things), 66 (heart), 129 and 131 (root unity)

II, 408 [selfhood], 409 [selfhood], 491 (self-consciousness), 495 (revelation)

NC I, 51 fn1 (radical unity of the ego), 55, 60 (central and radical unity of our existence)

Dooyeweerd speaks of an undifferentiated unity in the religious dimension of the horizon of our experience. And he speaks of a coincidence of all temporal meaning-functions in the supratemporal fullness of meaning.

However, he does say that this unity-identity is not a logical identity in the particularized sense of meaning (I, 44). That would amount to a monism like that proposed by Parmenides.