Proposition 5
Tag 0AD2, permanent. Cite it as [Bourbaki, Tag 0AD2].
Lie Groups and Lie Algebras, chapter III, § 4. Passage from Lie algebras to Lie groups
Let G be a Lie group, k a non-discrete closed subfield of K, G' the group G considered as a Lie group over k and (resp. ) an exponential mapping of G (resp. G'). Then and coincide on a neighbourhood of 0.
satisfies hypothesis (i) of Theorem 4 relative to G' and is therefore an exponential mapping of G'.
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.