It will not return any row because it is just a view. Usually the difference between tables and views are tables are suffixed with 'ALL' like po_headers_all. If you wanna select from the view then you need to setup the Org_id and then you can get the data

You have to set the org_id to retrive data from this view..

begin fnd_client_info.set_org_context('XX'); end;

where 'XX' is the relevant ORGANIZATION_ID for which you want to retrive data from hr_operating_units