Perform a search in the module "Files" by clicking on the magnifying glas in the black menu bar:
Type your searchword in the textbar and press enter to search or use the advance search by clicking the option "Advances search" to the right:
The page for the advanced search allows for a more detailed result. Enter all the applicable criteria for your search from the options on the page and click on «Start search» at the bottom to show all results matching your selections: 