All default controls in game UI are shown/hidden using scene manager. You can do the same.
Create simple scene fragment:
Lua Code:
local fragment = ZO_SimpleSceneFragment:New(yourControl)
or scene fragment with fade in/out animation:
Lua Code:
local fragment = ZO_FadeSceneFragment:New(yourControl)
And then add your fragment to all scenes where it has to be shown (in your case probably scenes "hud" and "hudui"):
Lua Code:
local scene = SCENE_MANAGER:GetScene("hud")
scene:AddFragment(fragment)
If you want to add more fragments at once you can create fragment group:
Lua Code:
local fragmentGroup = { fragment1, fragment2, fragment3 }
scene:AddFragmentGroup(fragmentGroup)
If you want to remove fragment/fragment group from scene use:
Lua Code:
scene:RemoveFragment(fragment)
scene:RemoveFragmentGroup(fragmentGroup)
You can find a few more about this topic here:
http://www.esoui.com/forums/showthread.php?t=1453