How to get a list of all branches across all projects/repositories

Our company has a self hosted GitLab install.

Our administrator has asked each of us to “go and find all the old branches you have on projects and delete them if they are no longer needed.”

We have roughly 75 projects. Over the past year, I’ve probably touched 25-30 of them. I don’t want to manually go to each and every project repository to look at the branches to see if any of them are mine to remove.

Does GitLab have this ability? To show a user a list of all of their branches across all of the projects in the repository? If so, please teach me how to do this.