Every filtered view of Projects is a URL you can share, and the same parameters come back in the address bar as you filter. This is the contract, so a saved link keeps meaning the same thing.
Projects
The list at /:directory/projects reads these query parameters:
A project's own pages are /:directory/projects/:projectId (overview), /:directory/projects/:projectId/activity, /:directory/projects/:projectId/issues, and each milestone has /:directory/projects/:projectId/milestones/:milestoneId.
Issues
The Issues list at /:directory/issues takes view=board for the board layout and label=<label> to narrow to one label — label=data-request is the view the old data requests page became.