this command puts a symlink of .env in every docker-compose folder
it creates an extra .env with a ~ like .env~ if the file already exists. Just ignore it. I could create a line of code that removes it

find /mnt/docker/docker-compose-files/ -mindepth 1 -maxdepth 1 -type d -exec ln -sbf /mnt/docker/docker-compose-config/.env {}/.env \;

remove every .env~ file in every docker-compose folder

find /mnt/docker/docker-compose-files/ -mindepth 1 -maxdepth 1 -type d -exec rm {}/.env~ \;

create a symbolic link in one specified directory

ln -sbf /mnt/docker/docker-compose-config/.env /mnt/docker/docker-compose-files/mongodb/.env

find the .env file in specified directory

find /mnt/docker/docker-compose-files -name .env