Within the Production under Production Settings, you should currently find a Document button which will produce a report of everything within your production. However, depending on the production size, this could easily be overkill.
2019 brings a new option called "Interface Maps" where you can get a graphical view of message flows, along with the processes, routers, and rules for the individual sections of your production. It's a lot cleaner than using the Documentation generator, but if you're needing to show multiple routes, you're likely to want to go through each one and take a screenshot. I also found that where I have a router with lots of rules/transforms, I need to scroll the screen to see the bottom of the display.
Information on this can be found here.