Variable used in web designer for it shop recipients

Hi Team,

Which variable used to refer it shop recipients in web designer like we use %userUID% for logged in user.

the use case is, in IT shop, admin will raise a request on behalf of user. We created a request policy in which admin has to select the business role before adding to the cart. only those business roles should be displayed which assigned to the recipients. with below query i can see the BR which assigned to logged in user i.e. in my case is admin.

XObjectKey IN (select ObjectKey from PersonHasObject where uid_person = N'%userUID%')

Please help.

Regards,
prasad