manually? if you open the developer console (f12), and at the bottom of the elements window should be a search bar (in most chromium based browsers). That search bar will accept css selectors as search strings.
It will highlight the element in the elements window; if you then hover over that, it will highlight in the page what element it is referring to (if said element is actually visible)
If the element isnt visible, right click on it, and your browser should give you an option similar to “Scroll into view”, (i’m using Chrome in my example here; it may look different for you depending on browser/os)
example: I have searched for “tr:nth-of-type(4)” on the main forum index here. It has highlighted this. I right click on the blue section.