I'd like to modify the default search form of Splunk (flashtimeline view) for a new app.
Therefore I'd like to add some search-strings to the search-field. These search-strings shouldn't be seen by the user. I think this would be a task for HiddenIntention module but read this module is deprecated, so I don't want to use it for a new app.
How can the task be done without the HiddenIntention module?
In the near term, you could certainly continue to use an intention; I've done this for precisely the reasons you describe. I placed an addterm intention in a local/ copy of the flashtimeline view for my app. Below is the module block I used: