@Riccardo_Mares, I upvoted too (and wouldn’t be surprised if this is part of Asana’s vision already).
In case you weren’t aware, in avatar menu > My Profile Settings > Profile tab, there’s a “Role” text field you can use as you wish now.
As you’ll see in the new Workload doc:
Asana is now using this within the product, in this case to allow you to filter, e.g., workload for all the PMs.
Otherwise, you could “manually” set up a project where each task is an org member and have a custom field for Role and that would enable you to see your org members in this way.