Default Decision Rule

do yo need to do it within the same form?

or is selection of Payment/Time-off on a entry form and selection of Payment Processed/Time-off captured on a task form?

is Payment Processed/Time-off captured selection an item column or are they approval outcomes defined in flexi task?

ok, clear.

first I would suggest  maybe an easier way how to deal with your task. since there is always 1:1 relation between original decision and approval task, the only thing what you moreless need is kind of confirmation that HR officer did process the task.

what I would do is that I would assign him a task with single possible outcome 'Task Confirmed'.

based on original request it is always clear that it means either Payment Processed or Time-Off captured.

that way you do not need to bother with complicated logic how to ensure consistent answers.

if you insist on the approach you drawn, then you can pre-select deault outcome with piece of javascript code.

something like this might work for you

NWF$("#"+Decision+" input:radio[value='12']")[0].checked=true

note you will have to determine first what are outcome values in your environment (12 in my case).

have a look here how to do thatUsing validation rules to ensure a comments box is not left empty