Visibility control is one of the most important things in C4D, especially in the editor, to keep track of what you are currently modeling. Cinema 4D offers visibility control on polygon level and on object level, and it allows to view objects in X-ray mode.
Since objects can inherit their visibility from their parents (the manual calls it "undefined" visibility, but inheritance is what it really is), setting the visibility on an object affects the whole branch (as long as the children inherit the visibility). C4D also offers the possibility to set all elements in a branch to the same level of visibility (by control-clicking the visibility icons). That is solution enough for most problems.
However, I have pretty often elements in the scene that are invisible by purpose, and should not be made visible by some automatism again: construction splines, alternative and optional parts in multi-purpose assemblies, or backup copies that I want to keep in place for a while. Obviously, the built-in mechanism that sets the visibility for a branch won't do here... and neither will the manual method, setting the visibility element by element.
The visibility tools essentially replicate the functionality of the control-click to the visibility icon: they set the visibility on a whole branch, either to "visible" or to "invisible" or to "undefined", for either the renderer or the editor. (That makes six commands, all in all.) Additionally, there are two commands that copy the visibility tags of the renderer to the editor, or vice versa, for the whole branch.
Set visibility command icons
Copy
visibility command icons
The icons use the same symbols as the visibility markers in the objects themselves, so it should be easy to figure out what command does what.
As with the Open/Close Tools, there is a stop tag here as well - that is what makes this functionality different. You may want to keep the visibility commands from affecting helper objects like splines or bones in certain situations, or to exclude an assembly from visibility without having it automatically be made visible again by a command that affects the whole branch. In these cases, assign the tag "Collie Tools - Block Visibility Changes" to the object, and the visibility commands will no longer affect that object or any of its children!
Block Visibility Changes tag
The tag does not prevent you to change the visibility manually by clicking on Cinema's standard icons, of course!
Again, like the Fold/Unfold commands, you will want to keep these commands in the object manager's toolbar. If there's not enough room, you can always group the icons to a common palette. The command I use most often is the "Editor - Visibility undefined" command to reset a scene's visibility after extensive work.
Named Structures will allow you a different approach to visibility, but you can use the branch visibility commands in connection with the Named Structures to get the most effect out of it.