I would like to know if it is possible in the Global - Gantt to only show the projects and tasks in wicht the user is involved personally or as a member of a group. I know it is possible to do it with the filters but I need to avoid the people to see everything before establishing the filters.

In other words:
I would like to have a CEO role who can see all the projects who include as a member the group (General Manager)

Also an Area Manager (i.e. Engineering manager) with some project managers under his responsability would be able to see his team projects but not the projects from another Area Manager (i.e. Operations manager)

I thought that would have been possible drawing the Organization Chart so the manager always sees the projects of his team (people under in the Chart)
I searched also into the options of projects and role permissions without success.

Thanks for your help.