Customizing Menus/Aggregating Projects and Posts

Hi! I'm using the Cleanportfolio theme (free). I'm looking to create Menu links that will lead to a page of all related tagged content — including both posts and projects. For example: I want to create a Menu button that says "Amsterdam" which will lead users to a page of all aggregate content related to Amsterdam, so both my projects of Amsterdam photos AND my Amsterdam related posts. I have considered using the "Search > Amsterdam" link which successfully shows all related Amsterdam content but it does not display the preview image for each (just a list of textual links). Project tags and post tags each have a different unique URL so I'm not able to use those. And projects do not allow me to use Categories. Is there a way I can fix this? My website is under construction (and too much of a mess to make public) so I'm not able to provide a link for anyone to view it at this time.