Your dog lies in a doorway and growls when a family member tries to pass. That narrow space is not a place to argue. Back away without stepping over the dog, reaching for their collar, or pushing them aside. Move people through another route if possible. Keep children and visitors away from the conflict.
A dog may be guarding a nearby resting spot or valued item, or may be frightened of people approaching in a confined space. Pain can make moving harder too. If the behavior is new, arrange a veterinary check. If there has been a snap or bite, use barriers to prevent repeats and seek a qualified behavior professional. Do not assume the dog is merely trying to be in charge.
Change the layout
Put a comfortable bed where the dog can rest without blocking traffic. Use a gate or close a door to prevent unsupervised access to the difficult doorway. Invite the dog to move before anyone needs to pass, using a familiar, positively taught cue from a comfortable distance. If they do not move, do not escalate into a standoff.
In easy situations elsewhere, reward your dog for following a cue to go to their bed and for moving away from a path voluntarily. Do not rehearse by repeatedly walking past a growling dog. A professional can help work out whether the core concern is a guarded space, handling, or the approach of a particular person and set a safe training distance.
The immediate success is a household where people can move without crossing a dog's warning line. Training follows that safety plan. For more on guarding a space or access point, see the resource-guarding guide, the immediate task is keeping people's path away from the warning area
Sources: Dogs Trust: Resource guarding in dogs. Dogs Trust: How to understand your dog's body language.