From the Roles main screen, choose the Role you want to modify by clicking on Details.
When the Role screen opens, the Permissions you see relate to the general Tab options at the top of the screen.
Choose the Permissions from this role. The permissions relate to the main Menu tabs located at the top of the page, with the exception of the Customers option, which relates to special functionality under the Customer tab.
Marking the box at this level would provide the Role access to all functionality under that Tab.
If you want to pick and choose which functionality a User Role may have, you would click on Show child permissions. This will expand the section, allowing you to mark the functionality you want for that Role.
When you have finished making your changes, click on Update to save your changes.