Bird goes after my dog and me while out on a walk

This mother bird with go up against any size creature to protect her nest!

I own a 6 year old German Shepherd. I was out with him, taking him for a walk, and for a few days noticed this bird kept swooping down at him whenever we passed that area. I got my phone out and recorded it on our next walk and what you see is the interaction that happened. I think the bird had a nest and was trying to protect it.