Hi Marc,
If you have created your applications using the SAPUI5 routing concept, you can create a route to a specific view in the other application with the ID in the URL.
Then it depends how you are enabling the SAPUI5 applications to your users. You could navigate directly to the URL, using a quicklink in an enterprise portal or via semantic navigation in a Fiori Launchpad.
Good luck!
Best regards,
Maarten