How to set up Departments and Sub-departments in Jira and assign permissions based on sub-department

[Roberto Fortunato]

We have a main project that has the following structure:

1 - Divisions

1.1 Departments

1.1.1 Sub-departments 

Tasks should be created under the each sub-department. How can we structure the Jira in a way that I can assign the permissions based on the sub-departments?