Hi @Sriram Pusuluri ,
The restriction applies to only UI action visibility.
To restrict closure of change to change_manager role you need to configure a before business rule.
1.Create a Business Rule on change table as below.

2.In the advanced section add the following script:

if (!gs.hasRole('change_manager')) {
    gs.addErrorMessage('Only Change Managers can close a Change Request.');
    current.setAbortAction(true);
}