# A 2-group $\mathbb{G}$, so that always exists $0 \to BG_b \to \mathbb{G} \to G_a \to 0?$

If $\mathbb{G}$ is a 2-group, does there always exists a short exact sequence for this $\mathbb{G}$, such that

$$0 \to BG_b \to \mathbb{G} \to G_a \to 0?$$ where both $G_a$ and $G_b$ are nontrivial (say, non-identity groups)?

(This is the following question of $\mathbf{B}A$ as a 2-group in a long fiber sequence approach from an opposite viewpoint.)