I have two Associated Items in a Transition, How to make only either or condition for only one Associated Item to be filled for completing Transition?

I have two Associated Items in a Transition, How to make only either or condition for only one Associated Item to be filled for completing Transition?

Hi I have setup 2 associated Items in a Transition for moving from one stage to another in Zoho CRM Deals Blueprint. 

For Example to move from Presentation to Demo Stage, The Transition requires Either to Log a Call or Log a meeting, before it can move to the next stage. So I added Call & meeting (Associated Items) in the Transition. But I want any one of them to be fulfilled so the Stage can move. 

There is no option to add an either or condition in the transition configuration box. 

Can anyone tell me how this can be done.

Thanks