Let $\mathcal{ G}$ resp. $M$ be a positive dimensional Lie group resp. connected complex manifold without boundary and $V$ a finite dimensional $C^{ \infty}$ compact connected manifold, possibly with boundary. Fix a smoothness class $\mathcal{ F}=C^{ \infty}$, H\"older $C^{ k, \alpha}$ or Sobolev $W^{ k, p}$. The space $\mathcal{ F}(V, \mathcal{ G})$ resp. $\mathcal{ F}(V, M)$ of all $\mathcal{ F}$ maps $V \to \mathcal{ G}$ resp. $V \to M$ is a Banach/Fr\'echet Lie group resp. complex manifold. Let $\mathcal{ F}^0(V, \mathcal{ G})$ resp. $\mathcal{ F}^{ 0}(V, M)$ be the component of $\mathcal{ F}(V, \mathcal{ G})$ resp. $\mathcal{ F}(V, M)$ containing the identity resp. constants. A map $f$ from a domain $\Omega \subset \mathcal{ F}_1(V, M)$ to $\mathcal{ F}_2(W, M)$ is called range decreasing if $f(x)(W) \subset x(V)$, $x \in \Omega$. We prove that if $\dim_{ \mathbb{ R}} \mathcal{ G} \ge 2$, then any range decreasing group homomorphism $f: \mathcal{ F}_1^0(V, \mathcal{ G}) \to \mathcal{ F}_2(W, \mathcal{ G})$ is the pullback by a map $\phi: W \to V$. We also provide several sufficient conditions for a range decreasing holomorphic map $\Omega$ $\to$ $\mathcal{ F}_2(W, M)$ to be a pullback operator. Then we apply these results to study certain decomposition of holomorphic maps $\mathcal{ F}_1(V, N) \supset \Omega \to \mathcal{ F}_2(W, M)$. In particular, we identify some classes of holomorphic maps $\mathcal{ F}_1^{ 0}(V, \mathbb{ P}^n) \to \mathcal{ F}_2(W, \mathbb{ P}^m)$, including all automorphisms of $\mathcal{ F}^{ 0}(V, \mathbb{ P}^n)$.
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