Users report different behaviors of the Search function on the Add Rule menu (on the Audience page) versus the Add Content menu (on the Content page) for Campaigns+. See an example below:
Searching "like" on the top level (no category selected) Audience tab ends in the rule showing up as a result.
In the top level of the Content tab, the same search has no results.
However, if you go to the intended category and search for the same string, "like", you get the intended result:
The Content tab of the Campaigns + portion of the CDP application
There is not a known workaround at this time.