UI or HUDs are usually placed on a LAYER above the game level and the LAYERS parallax and scaling amounts set to 0,0 and 0
this way it will always stay on the screen even if the player moves around
you can also use the Anchor behavior to fix it on the screen position
step 1 create a new layer above your game level using the layers tab in the project tree and name it "UI" or "HUD"
and set the parallax and scale settings to 0,0 and 0 for scale ( it can help to show parallax in the editor as well by checking the box...where it says so)
step 2 place all of your UI objects into this layer
they should now "float" above the game level
hope that helps