Hi Maja.
It's not possible to add a freeform search like that. This isn't quite what you asked for but you could define story actions in the description text in your Map Series, such as in the first tab that your readers see, that take them to different tabs in your Series. So a reader could click on a story action link in your description text for a particular topic and get taken to the tab that contains the Map Journal about that topic. You can also add story actions into a Map Journal's narrative text to take people to a particular sections in that Journal. But you couldn't make a story action in a Map Series tab that takes your readers to a particular section in an embedded Map Journal.
Rupert
