Once you hit Search, you'll see the query URL in your browser with different parameters in it. So, what you do is append the gl=country code to the query. For example, if you need to check local search results relevant to the US (to make it look like you are browsing from the United States), add gl=US to the URL.

1] The question mark separates the main part of the url from the query string. In the string hl=en the hl stands for host language and en stands for English. Here is an example of one in German. https://www.instagram.com/p/BdRSEciDn4f/?hl=de.