PGC Link共有三種，"Go Up"主要就是用在回上一層的PGC連結，
類似像檔案總管的回上一層的意思，對應的按鈕指令是"Return"，
不過我自己卻很少用到，而且不知道有哪些地方會有需要應用到。

以下資料摘錄自Scenarist 說明檔：
Prev PGC Link Creates a link that returns play to a PGC that played immediately before the source PGC.
The Previous PGC link is executed when the viewer presses Prev on the remote control.

Next PGC Link Creates a link that advances play to a PGC that plays immediately after the source PGC.
The Next PGC link is executed when the viewer presses Next on the remote control.

Go Up PGC Link Creates a link that returns play to an earlier PGC, usually at the beginning of the sequence
or at the top of the current major branch. The Go Up PGC link is executed when the viewer presses Return
on the remote control