Have two parts on one stave but have separate parts

For the future, it would nice to be able to have written 2 parts on the score and that take up one stave, then when making parts, have each printable by itself. For example, have a first trombone and a second trombone part. They are two different parts, but only take up one stave on the score, but are two separate parts. If I were to print them, I could a trombone one part and a trombone 2 part. This would be great for minimizing space used on those big score with lots of instruments.