In my source code within Bitbucket, I can click on any file and view all of the commits of that file:

However, I would like to know which pull request that commit was associated with, but if I click on the commit, I don't get that information:

This information would be really useful for traceability as well as figuring out all of the relevant code changes for a particular commit, say if someone had to port the changes to another program. 

Right now I can guess the pull request by looking at all merged pull requests with author near that date, but it's cumbersome to do so.