Composite role: A group of one or more roles for administrative purpose is refereed as composite role.
Step 1- go to PFCG
enter composite role name and then click on "comp role"
Specify the description
In composite role it doesn't contain authorizations tab.it is nothing but group of one or more roles.
Specify the roles
Click on Read menu tab.when you click on this read menu tab then it will fetch authorizations from the single roles.