Christine Milne led the Australian Greens from 2012 until 2015. During this period, a select number of members of the parliamentary party served as official spokespersons for the party both inside and outside of Parliament on various issues, each member being assigned portfolios for their speaking duties. This allows the Greens to shadow government policies and actions from the party perspective.
. This allows the Greens to hide government policies and actions from the party perspective.

I think shadow in this context means hide.
( z0 allow :ARG0 ( z1 this ) :ARG1 ( z2 hide :ARG0 ( z3 political-party :name ( z4 name :op "The" :op "Greens" ) ) :ARG1 ( z5 and :op ( z6 policy :ARG0 ( z7 government-organization :ARG0-of ( z8 govern ) ) ) :op ( z9 act :ARG0 z7 ) ) :ARG2 ( z10 perspective :poss z3 ) ) )
(z0 / allow-01
    :ARG0 (z1 / this)
    :ARG1 (z2 / hide-01
              :ARG0 (z3 / political-party
                        :name (z4 / name
                                  :op1 "The"
                                  :op2 "Greens"))
              :ARG1 (z5 / and
                        :op1 (z6 / policy-01
                                 :ARG0 (z7 / government-organization
                                           :ARG0-of (z8 / govern-01)))
                        :op2 (z9 / act-02
                                 :ARG0 z7))
              :ARG2 (z10 / perspective
                         :poss z3)))
. This allows the Greens to hide government policies and actions from the party perspective .
z0 :ARG0 z1
z3 :name z4
z4 :op1 1
z4 :op2 0
z2 :ARG0 z3
z0 :ARG1 z2
z7 :ARG0-of z8
z6 :ARG0 z7
z5 :op1 z6
z2 :ARG1 z5
z5 :op2 z9
z9 :ARG0 z7
z2 :ARG2 z10
z10 :poss z3