On a product overview, use the search box at the top. The list shows rows that contain the text you type.
To match any of several terms, separate them with a semicolon or a vertical bar:
juice;soda juice|soda
Each finished term is shown as a pill in the search box. A row stays in the list when it contains any of the pills. Press Enter to keep the word you are typing as its own pill. A semicolon or bar at the end, with nothing after it, does not add an empty term. A comma stays inside the term.
Click the × on a pill to remove that term. With the box empty, Backspace puts the last pill back into the box so you can edit it.
The button at the top left of the overview sets how many rows are listed. The choices are 15, 25, 100 and every row. The overview remembers the search and the row count in this browser.
To search the text on a product you already have open, see Search on a product, and the GTIN dialogue.
Tick rows, or leave them unticked and keep this search, when you export to Excel. See How to import and export with Excel.