Highlight records Tracking Events and other metadata about sessions to make them easy to search and filter. Start with the Quick Search that will find the best matches depending on what you're looking for and customize your query further in the panel above the sessions feed.
When using Highlight, you might be interested in querying for sessions where a user clicked a certain HTML element. Highlight records users' clicks on the page as two queryable properties: clickSelector and clickInnerText.
You can also visualize what Highlight is tracking by looking at your site's console logs when you click an element of interest. For example, clicking a particular p element in https://app.highlight.run/ prints the following in the console logs.
You can then use the session filters to search for text in the two fields.