This is a very general question. With the information you’ve given, you should only expect general responses. To give a proper answer one would need to know much more, for example, the size of your business and the importance of each unit.

A few general principles:

Consider an experienced consultant outside of your business rather than hiring another employee. You will likely need very objective hard advice and it’s possible that the advice might include cutting one or two of those business units to help you achieve the kind of focus you need to succeed in a business.

Wishing you the best!