On User Choice, set variable type nodes, allow to set only single column value.

There is no way if it require to update multiple values in same node. This can achieve using adding multiple set variable nodes but it is not user friendly as well as execution of same is independent of sucess of Node. This may cause workflow nodes changing status updated but related variable set has failed.

Design:

Adding Variable sub tab which visible when action is either of User Choice, Set Variable or User Task,

Variable tab should have field for specifying column which specify target column name on PO. And there is Attribute Value field allowing to specify constant value or context variable.

Future Enhancement:

If Attribute value is null then expected to get value as input from user. So for example when user approving workflow, they can be represented with some mandatory field to fill.