How to set roles for Functionals

Hi Experts,

We are having Functional SD, HR,FI,Co,MM,PP Basis and Abap,

We would like to assign only Particular Functional Roles for different Functionals

means all the functional other than Basis and Abap must mot access the T-code of Basis/Security

I had gone through the doc providing all authorisations except basis transaction codes but can't solve my problem

Hope i can get a solution

Regards

SROY