You have to use "ALL" in the Strategy Create panels.
So when you are in the Strategy create panel "DML Activity Report Options"
select this option
Set LOAD Options==> Y
which puts you into this panel
"DML Load Format File Options"
Where you get to decide the options for your output file
here you will see this
REDO / UNDO Data ==>A (R-REDO ,U-UNDO ,A-ALL)
So this is where you set A for All.
Carry on through the panels to build your strategy
In your Job you will see these parms
INCLUDE (REDO , UNDO , TIMESTMP, URID , LOGRBA )
So its having both REDO and UNDO which will generate both the before and after records
here is an example
PLANETK UA 2017-03-06-11.47.18.000000Uc << After
PLANETK UB 2017-03-06-11.47.18.000000Ua << Before
PLANETK UA 2017-03-06-11.47.18.000000Ud
PLANETK UB 2017-03-06-11.47.18.000000Ub