  We study the soft behavior of QCD amplitudes with multiple hard legs and
present a compact expression for double soft gluons and double soft quarks at
one-loop. The color correlation of the current basically shows a dipole
structure which couples to two hard legs at one time, except for a simple
abelian contribution which factorizes as products of one-loop and tree-level
single soft current which couples up to three hard legs. The kinematic
dependence can be expressed in terms of polylogarithms (at least up to finite
terms in $\epsilon$) and the results were displayed with time-like kinematics.
Analytical continuation to other kinematic configurations is then discussed
where we found non-trivial crossing into ingoing states. The amplitude squared
is always crossing invariant, which leads to the fact that the fully
differential soft function (and the TMD soft function) is universal up to
three-loop.
