Forum:Level Creation: How do you select objects behind other objects?

So, i'm new at this, and maybe those are stupid questions but i didnt find any answers to them:

How do I select an object on the back layer when there is an object in front? Can i make a layer 'invisible' to work on the back layer?

Can i make a bolt that connects through more than one layer? I'm gonna try to make a drawing to explain:

this is viewed from the side (aka not from LBP perspective:

= -> Bolt

[ -> Thin Layer 1, cardboard

G -> Thick Layer, Grabbable)

] -> Thin Layer 2, cardboard

1 2 3

=[GGGG]=

[ ]

[ ]

[ ]

[ ]

so, i'm trying to place a bolt that would go through both thin layers and the grabbable object in the middle. If i create layer 1, add layer 2, put a bolt, then add layer 3, put another bolt, layer two cannot 'turn'.. its double bolted and fixed.

my other problem is once i've done this, i cannot select the bolt in layer 1, since there is another bolt 'in front'...

Seems to me to build something in LBP you have to really plan in advance, cuz once you put something in front, you cant modifiy anything behind..

Is there any ways to save shapes as brushes? or stickers as brushes? (for material).

Thanks in advance for any answers, and sorry for my poor english!