The bath water is not hot or cold. It's in between.
•A sandwich consists of two slices of bread with some other food in between.
he likes wine before, after and in between meals - он любит выпить вина до еды, после еды и в промежутках
между
he likes wine before, after and ~ meals - он любит выпить вина до еды, после еды и в промежутках