For example, if I have multiple courses in Brightspace, and I wanted to search through all of them to see if I used a specific YouTube video or a link to an external website, etc., in any of them, is there a way to do that?
At present, there is no global content search functionality available in Brightspace.
Now, depending on what content experience you are using, you may be able to perform a topic name search at the course level. At present, only the Classic Content Experience has the ability to search content topic names (at the course level). If you are using the New Content Experience, you may attempt to workaround this by using browser search, which will search only the text rendered on the page at the time you perform the search.
That said, to cast your vote for global content search as a feature, I would invite you to vote for this idea in the Product Ideas Exchange (PIE). PIE is designed for users like you to send direct feedback to our Product Development organization and has the following advantages:
Finally, another alternative, although this would require access to Data Hub, is to pull the content-related data sets to get a picture for what content objects live in your courses. Typically Data Hub is access-restricted to Administrators, so if you do not have access you could reach out to your Organization's Brightspace administrators to download / join the appropriate data sets for this exercise. If you are an administrator, you will likely be looking at using/joining the following data sets:
I hope that helps!
Learning Administration Manager