How to rebase off master with github client?

I’m used to a workflow on the command line that doesn’t seem to be able to translate to the GitHub client GUI.

I branch off master, do some work, other people do work, other people merge their work, I git pull my master branch, I rebase my branch off new master, then I PR and merge my branch.

I just am not seeing how I can rebase off an updated master with GitHub GUI? I REALLY like to keep all my commits for a particular PR and branch grouped together for a log that looks like:

merge my stuff
my commit 3
my commit 2
my commit 1
merge dev-a's stuff
dev-a commit 3
dev-a commit 2
dev-a commit 1

Git Baby is a git and github fan, let's start git clone.