How can I set a person for execute just the transitions they are atributed for?

[Brenda Albuquerque]

I have a BPMN worflow and there are characters especified that i don't have on the Jira worflow. So, I want to especify a character in every transitions, resulting in a more similar way of BPMN. I Know that I can setting this on the "conditions" but I'm not succeed in that. 

[Kevin Johnson]

In conditions set ---- user in groups , user in project role , can be used to set conditions and hide transition from user option can be used to hide it from other users.