There are two ways to give a user multiple roles. The first is to create a new role that includes all the permissions of the other roles. The second is to add the user to each of the desired roles.
The first method is preferable if the roles are static and do not change often. This avoids having to update the user's permissions every time a new role is created or an existing role is modified. It also eliminates the possibility of accidentally forgetting to add a user to a role.
To create a new role that includes all the permissions of the other roles:
1. Navigate to Administration > Users and Roles > Roles.
2. Click New Role.
3. Enter a name and description for the role.
4. Select Include All Permissions from Other Roles in this Role checkbox at bottom of page . click OK button . now u can see newly created role with childs(roles).
To add the user to each of the desired roles:
1) Go To People tab ->select User->click on edit icon (pencil).goes into detail page of selected user 2) go down find section called Roles->click on Select Rolesbutton 3)select multiple roles using ctrl+click or cmd+click 4)once done selecting required roles,hit Done button(check mark icon) at top right corner