At the top of the 'Stock Settings' page we have a section where you can search for stock (See image below).
If you know the stock item name you can simply start typing in the 'Search Stock' box and then press 'Enter'. The results will then be returned.
Alternatively you can click on 'Advanced Search' and this will bring up the screen below. This shows the fields you can search by. Once you have populated these you just click 'Search' and this will return the results. Alternatively you can click 'Cancel' to close the screen or 'Clear' to clear the search parameters.