Hi Unconnected ,
further responding to duditon 's answer, you could also try and set your containers elements origin points to position your containers elements on spawn.
For example, if you have object A and B in a container, and you want object B to be 100 pixels south of object A, then simply put object B's origin point 100 pixels above its center, and the object will spawn 100 pixels south of where it "should" have spawned.
This can help you a lot positioning everything in one go, without having to have any events positioning stuff for you, and also retains every object's position, even on object destruction. The problem is that it's tedious to set up properly if you have lots of objects in your container.
Another solution could be the one I use in my game in progress, which have about half a dozen menus stacked on top of each other : Put every menu in it's own layer (1 layer per menu), set them up how you want them to be set up, and make them appear/disappear by making the layer appear/disappear.
The only problem with this is that every clickable object will still be clickable , even when invisible. You will only need to make these objects unclickable by using a boolean , off when the layer is invisible, and on when the layer is visible. Pretty simple stuff.
Hope this helped !