  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
$\mathcal{F}^{0}(V, \mathbb{P}^n)$.
