On almost any view inside of a Bitbucket repository a project and repository name is output in the top of the main frame. It's looking like a kind of directory listing (in HTML unordered list with the class name repository-list used).

If you go into a pull request overview (URL /pull-requests/#/overview) you don't have this listing.

So if you switching between different tabs and go back after a while, you need to switch for example to the files view, to know which repository you are in.

Ok. At the end, also the Browser URL is telling about. But getting the repository-list inside of a pull request overview would be more comfortable.