Back to disc 1 or disc 2 menu

ok so i got the dvdremake, and merge and when i first put in the disc everything is great, i can select which of the two discs i want… problem is, the navigation back to that first menu ( disc 1 or 2) I cant seem to get there.
can someone help me identify just what the PGC main title screen is, so i can set a call to it?? actually scratch that, can someone simply say, how to make it so if i hit menu, it goes back to the first menu

Just press Title menu on your remote or in the software player to get back to the disc selection menu, which is always at the last VTS menu after doing the merge. If you want to reprogram one of the buttons in the disc 1 or 2’s main menu to go back to the disc selection menu, use “Jump VMG Title menu” command.