Microsoft Teams has an easy to use advanced search located at the top middle of the application (see screenshot below)
- Click into the search bar and type in your specific search term, press "Enter" or click on the search dropdown beneath your search
- The left pane will now show your search results. At the top of your left pane you can filter your search results further by clicking between "Messages", "People", and "Files"
- For an advanced search, click on the filter icon to the right of "Messages", "People", and "Files".
- The advanced search will give you further options in narrowing down your search results.