The Decompose command attempts to decompose a polynomial into a composition of simpler polynomials.

$\mathrm{with}\left(\mathrm{MmaTranslator}\left[\mathrm{Mma}\right]\right)\:$

$\mathrm{Decompose}\left({\left(x^2+1\right)}^2+5\right)$

$\left[x^2+2x+6\,x^2\right]$

$\mathrm{with}\left(\mathrm{MmaTranslator}\right)\:$

$\mathrm{FromMma}\left(\mathrm{`Decompose[\; (x^3+x^2+4)^2\; ]`}\,\mathrm{evaluate}\right)$

$\left[x^2+8x+16\,x^3+x^2\right]$

The MmaTranslator[Mma][Decompose] command was updated in Maple 2017.