OCLC and ProQuest have now developed a better experience when searching OCLC's WorldCat Discovery and selecting ProQuest content. When a user runs a search in WorldCat, and then selects a ProQuest database recommendation from the Additional Databases section, users and their search queries will be taken to their institution's ProQuest databases. Users will then be able to continue the results of their search within ProQuest without having to perform the search a second time.
To set this up, there is some configuration needed within OCLC. The instructions can be found on OCLC's Knowledge Base, here.
If you have any questions, please contact ProQuest Technical Support.