Resume returns to the last played title. Look for the [I]resume[/I] command by start tracing from the root menu. There will be some [I]if[/I] statement with some R[x] that determines whether to resume or not.
You can add additional logics to go to the special features menu before this check for [I]resume[/I]. In the special features menu, when the third button is pressed, set an unused register to 1 before branching to the graphics. Then in the menu pgc where the [I]resume[/I] command resides, insert the [I]if[/I] statement [B]before[/B] the [I]if[/I] check for resume to check if the unused register is set. If it is, then branch to the special features menu. If not, then execute the next [I]if[/I] statement. Also, be sure to reset this unused register to 0 when you’re in the last graphic menu.
If in doubt, post some screenshots of the associated commands (pre/post), or even better attach the menu shrinked VOB along with the IFOs (convert all menus to still, you can blank the middle graphic menus if you want to, disable the menu audio, and export modified files to some folder, zip this folder, and attach it here).