Assume your main menu is called groupA and your detail menu is called groupB and each menu is the size of the screen. Then when you click on an option in groupA you transition groupB under groupA and move groupA left by 50%.
Assuming a screen width of 320px (center at 160px) and each group is 320px wide, groupA is at x=160 and groupB is currently at x=480 (i.e. not visible)
Some code…
--onclick on groupA (groupB slides in from right) transition.to(groupA, {time=500, x=80}) transition.to(groupB, {time=500, x=160}) --onclick on groupB (i.e. close the child menu and slide groupB to the right) transition.to(groupA, {time=500, x=160}) transition.to(groupB, {time=500, x=480})
If you wanted your sub menu to scroll from underneath your main menu then you position groupB at x=-160 and stack it below groupA and use the following
--onclick on menuA (groupB slides under from left) transition.to(groupA, {time=500, x=-80}) transition.to(groupB, {time=500, x=160}) --onclick on menuB (i.e. close the child menu and slide groupB to the left under groupA) transition.to(groupA, {time=500, x=160}) transition.to(groupB, {time=500, x=-160})