Merge check to block pull request if commit or branch doesn't exist on named branch

[mtrobbin]

I need a merge check that will enforce the user to merge their feature branch to the dev branch before they merge to the staging branch. So, when they do a pr to staging I want it to check that the commits in their pr exist on the named dev branch. Or even I suppose it could check if the branch has been merged to the correct prerequisite branch.

Does anyone know how to set something like that up?