The 'Find' button in the Library and Add Component dialogs will help you to find the item you are looking for.  There is also one in the Change dialogue within a component's properties

Once in the Library Manager, click on the Components tab.
Click the Find button. The Find dialog is displayed.
As a minimum you must choose one selection criteria. If you choose Name, the drop down list to its right will allow you to choose ‘Is Exactly’, ‘Starts With’ and ‘Contains’ as filters.  Other selection criteria have their own filters as appropriate.
Type the text you wish to find in the entry box to its right and press the Find button.
In the main results pane (if any items match the search criteria), you can select an item using a single click. This item will then be selected in the Component panel of the Library Manager.

This principle also works if using the Add Component dialog. In this instance, you can also use a double-click to add the Component to the design.