You can search the project by typing in a keyword at the search text input.
If you type in a keyword, only the objects that match the keyword show up in the tree on the left-hand side. The matched keyword will be highlighted. The search is case-insensitive.
The search targets are the following.
Data Frame name
Report (Note, Slide Dashboard) name
Report (Note, Slide Dashboard) description
You can click the 'x' icon to quit the search.