access to view the request for different user

access to view the request for different user

Hi

I have an interesting question
whether the user can give access to view his request different user?
if so, how?

for example:
I requestor role access sdguest created the request. This request I see in my self portal
I want a different user also has access to this request and has participated in decision
How can i do this?

Thanks for you help