What you want is called a "volume". When running a docker container you just pass in the -v option and it maps a directory outside the container to a path that can be used from inside the docker container, e.g. `docker run -v /host/directory:/container/directory ...` would make the directory /host/directory on the host machine accessible inside the container at the path /container/directory.
While you can directly map the host filesystem to the container filesystem in the manner you describe, that's referred to as a bind mount, not a volume. Volumes reside in the host filesystem as well but are solely managed by Docker.
Outside of trickery requiring the use of bind mounts (I use one to share ~/.ssh between a host user and container user, for example), volumes are recommended.
https://docs.docker.com/engine/admin/volumes/volumes/