Need to hide the Reject button verses specific WF. process

Hi ,

a more clarification on my question , This is related to a seeded SSHR process called Extra Information Types that are used a WF. process Called HR_EIT_JSP_PRC over the seeded function called HR_EIT_SS ,

So, once the user request it and go for the required approvers based on every customer design per his business needs , the approval receive a self service notification over the system and over the email with the full request details that need from approves to take an action those action by choose one between a several buttons located over the sshr page which is (Reject, Approve , request more information ,delegate or reassign to another approver ) as per the attached screen shot