Changing states of Buttons on Main Menu

States don't transfer between slides. You'll want to transport that status with a variable. So when you reach a completion event for your segment (like when you finish a quiz or hit a specific slide) you'll change the variable contents.

s1Complete (True/False - default False) - adjust variable to true when the page / event is hit

Now on your main menu, setup a trigger to change the state of your object or button to disabled on timeline start but only if the condition is met: s1Complete == True.

Here's a file I built way back in the Beta. It contains a feature you can't accomplish anymore (writing to a results score variable - unsure why this trigger target was removed, have been begging for it's re-addition). Other than that it demonstrates what you're looking for with the section / menu completion.