A folder search lets you search PDF files in one folder (with or without sub-folders) and lets you limit the search according to values in standard fields (author, title, subject, keywords, etc.) of the PDF Properties.
To search in a specified folder
Click the Search tool in the Home ribbon to open the Search dialog box.
Type in a search phrase.
Choose Selected Folder from the Look In drop-down list, and browse to select a target folder in the Browse for Folder dialog box. The selected folder (local or network folder) will be displayed in the Look In box.
Select search options; for folder searches you have an extra option: Include Subfolders. Select it to include all sub folders.
Click >> Advanced to use additional search criteria. For details, see Selecting Search Options.
Click Search. The Results list will show the occurrences.
Click a result in the list to display the appropriate page that contains the search result highlighted.
Note
If you have folders with a large number of PDF files you do not plan to modify much, searching can be faster if you generate an index for them and use index searching.