Clicking around is the best way to understand how the search function works. You can use parenthesis in a search to find devices that contain one term or another. For example, if you want to find devices that have the tag third floor or fourth floor, you can type
Tags=(third floor or fourth floor). Similarly, you can replace the parenthesis with quotation marks to search for an exact term.
From the customer view in https://admin.webex.com, go to Devices, and then narrow down your results by using these filters as needed: