Selecting status menu items (those little icons in the right hand menu bar) is difficult primarily because there is no easy way of specifying them - they don’t have names so its hard to identify them.
You can use a Click at Found Image, although even that can be difficult as they often animate or change icons based on various states. If the icon does not animate or change state (or has a known state when you want to select from it), then this can be a good solution, followed by Insert Text by Typing “Menu Name%Return%”
To click relative to an image, you use the Mouse Click action, configure it to be relative to a found image, and take a screenshot of the desired area of the screen using Command-Control-Shift-4, and paste it into the image well on the action. The image has to be unique (which includes not being visible in the action if the image is small enough not to be shrunk in the image well) otherwise Keyboard Maestro will not know where to click. The Display option in the action will allow you to see where Keyboard Maestro is matching.
I have looked into it on multiple occasions, and will no doubt look in to it again, but its a difficult problem.