You can use ticket fields and saved ticket searches to do just that!
Create the ticket field you want to use to tag tickets
Go to Settings (Admin Header) -> Click on "General" in the drop down menu -> Click "Ticket fields, queues and rules" -> Click "Ticket Fields -> Click "Add a new custom field..." -> Create your custom field.
Create a custom search for tickets with that field
Okay, you've created the ticket field, you've "tagged" the related tickets. Now, how do you get a list of just those tickets?
1. Start by doing a ticket search (check out this article for all the different ways you can search ). For this example, I used status:open "Product Area":"Widget"
This brings up any open tickets tagged with the ticket field Product Area:Widget.
2. Click on the gear icon by the search bar and choose "Save search as..." and choose a name. For this example, I chose the original and insightful name—"Widget Tickets"
Each saved search is unique to you as an admin. So you might use 6 saved searches while another admin has 10 they use.