Security Approval Hierarchy

Hi Gurus,

I have a different hierarchies on the system, I have a requirements to apply a security access on the document so that only Owner, subsequent approver

in addition to individual employees can see the documents.

I have applied the Hierarchy security Method in document type, Now owner and  subsequent approver can see the document, but I still need to allow some individual to see the document as well.

those individuals are not existing in the original approval hierarchy, I did include them in the security hierarchy on the top of the approval

but they still not be able to see the document !