if you place an item it now gets auto aligned to the level floor.
say i build a bottom floor using prefabs when i want to add a second floor using prefabs i can get that on top aligned to the bottom floor.
same goes for e.g. placing a bridge using extract makes it easier but does not work if you want to use different bridge parts.

Are you asking about placing an object on a second floor of a building? If so; what you want to do is place your entity on the ground, just outside of the building (to make it easier to view). Then left click on it again, and select "position" in the widget menu (should already be selected by default). Use the green arrow to move it up to what you thing the second floor level is. Then use the WASD keys, or arrow keys, to move the entity over (make sure you haven't deselected it yet). Now select "properties", in the Widget Menu. From there, you can use the "pageup/pagedown" keys to fine tune it's placement on the Y Axis (up and down); and the arrow keys for placement on the X and Z Axis (forward/backward, left/right). Use the mouse scroll wheel to zoom in and out, and left mouse button to swing the view around; while placing your object...to get the best view.

This can be tricky; but will give you the best placement control in tight, or multiple level environments. Let me know if this helps.

i am the lazy kind of person and hoped i could skip the manual steps you mentioned and have the second floor auto snap onto the first floor.
i wil try to use them and see if can get my second floor placed this way for now

Yep; I understand. Quick tip: If you're placing multiple items (crates, for example) on the same level; use the extract tool to create multiple instances. Then go back and rotate/position/scale each one to your requirements. It's a good suggestion for future editor improvements!