Add extra followers
If you have permission to edit an item, you can add other Followers if you think they should know about content QSToolbox. e.g. you reported an Incident and want the area manager to know about it, or perhaps the sales manager ought to be aware of a new Product Data Sheet document.
Look for the Followers tab on the right when you're viewing the content item:

Search for who you want to add and then click on their name in the search results to select the user.

When you have selected all the followers you want to add, click on the 'Add Followers' button at the bottom.

To have permission to add other users as Followers to a content item you'll need to be the "Assignee' for the item, or be in the relevant module-managers group or a 'Staff' user.