At the point of asking question, I was unware of the fact that Picklist values can be collected in single text variable using Add function in the loop.
Lest say that the single text variable is
Textsinglevar where all the picklist values gets collected using loop and
textvarStage (New/open/Prospecting/....) .
Textsinglevar (New,New,Open,Prospecting,Propecting,New,Nurture, Demo Booked, Opt-out, Opt-out) is used in decision element to see if it
Contanis first the highest priority stage and another decision branch to see if the second highest priority is collected in
Textsinglevar and so on. So the decision element first checks the highest priority stage from first branch and second branch will check second highest priority stage and so on.
Textsinglevar should be text to use with contain or else it has to be picklist to compare with picklist variable on value, which can be done using single picklist and assigning required value to it.