version: '3'
services:

  neo4j:
    image: neo4j:3.5.5
    volumes:
      - ./conf:/var/lib/neo4j/conf
      - ./mnt:/var/lib/neo4j/import
      - ./plugins:/plugins
      - ./data:/data
      - ./logs:/var/lib/neo4j/logs
    restart: always
    ports:
      - 7474:7474
      - 7687:7687
    environment:
      - NEO4J_dbms_memory_heap_maxSize=4G
      - NEO4J_AUTH=neo4j/123456
    networks:
      - my-network

networks:
    my-network:
      driver: bridge

first look at what the previous network is actually called:

[[email protected] cutter]# docker network ls
NETWORK ID          NAME                          DRIVER              SCOPE
1918b6df97b5        bridge                        bridge              local
cd415863acc5        docker-neo4j_my-network   	bridge              local
ee4b01a94aad        host                          host                local
0f77a2b4f416        none                          null                local

You can see the original name of the original network to add the name of the original project directory, so the second docker-compose file is as follows:

version: '3'
services:

  [service2-name]:
    build: .
    image: [service2-image-name]
    restart: always
    networks:
      - docker-neo4j_my-network
	...

networks:
  docker-neo4j_my-network:
    external: true