This tool allows searching within the data contained in the grid or within the text content of the listed documents. In contrast to the DBSearch tool, here we can define the fields to be searched.
The search button works according to the state of the find from selector, starting the search either from the selected document  or from the first document in the list.

The filter button removes from the grid (temporarily), all files not matching the search which has been performed.
Also in this case, the search is performed according to the state of the filter from selector, either on all documents on the grid or only on the ones which are visualized (some documents may be not shown on the grid due to a previous action).

The unfilter button undoes the filtering action and makes all the contained documents visible on the grid.

If on the fields selector the contents checkbox is activated, the words to be searched will be looked for in the document text and only there, since it is not possible to perform a search both in the document content and on the database fields. This search option is more slow, but the output will be very useful, since you will be give the exact line containing the searched word, as you can see in the following picture.