I recommend story mapping[0..2]. It facilitates seeing your backlog across goals and activities, which may span projects. With a more focused backlog, you can then prioritize within specific scopes.

The main downside is tooling. Unless you are using a physical board, you'll probably want/need a SaaS.

[0] https://www.jpattonassociates.com/user-story-mapping/

[1] https://agilevelocity.com/agile-tools/story-mapping-101/

[2] https://www.thoughtworks.com/insights/blog/story-mapping-vis...