The Forgotten Realms has a few options for nature-loving religious types, but no, there is no single 'God of Nature' and BG3 has none of them available at present.
Eldath, Goddess of Peace (NG)
Malar, God of the Hunt (CE)
Mielikki, Goddess of Forests (NG)
Silvanus, God of Wild Nature (N)
It covers most 'shades' of druid, and there are others who cover aspects that might appear to be part of the natural world (Umberlee's sea aspect being an example). Of course, each campaign is slightly different so some deities might be removed or shuffled off to other duties.
So far, BG3 hasn't included any of them, but with Druids making an appearance, I imagine that Silvanus at least will be an option.
Yup, what I meant was that Early Access offers none of those
There is no Nature god to chose from on the list.
