You can use “Get All Widgets Of Class” to find the widget you want to touch, then call any functions that are in that widget to do your desired action.
So in your main menu have a function that unhides itself when called. Then in your options menu call “GetAllWidgetsOfClass → MainMenu” → “Unhide MainMenu function”.
Alternatively (and probably less performant), you could probably also put a variable on your character or in your game mode, that those widgets then watch to determine if they should be visible or not.
Basically, “isInOptionsMenu” bool on your character, and the MainMenu/Options hides/unhides itself whenever that value changes.