So there is any other way that I could build that without a script?, because the only thing that I need is that a user if he is in the group PA , then will execute the PA, or if the user is in the group AM then will execute the AM action. Each user is in a specific group and they are only in one, they don't share other groups.

I was just trying to find another way more easy then to have to include all the users from each group individually separated in each condition, so when the need of any alterations come, i will not have to worry about and not having to come to workflow to change.

Thanks for the help!!

One possible way you could do it is duplicate this business process and add security rules so only that particular group can start it, which means you'll always know which group you're dealing with.

Depending on how you want the reporting options, you could have totally separate business processes for each group or you could use the same main business process and have each groups' specific business process use "Invoke Workflow" to start the main one, passing in their group name as a parameter