Regardless of whether you use TTC or not:
short tutorial on Acrobat Bookmarks: https://www.evermap.com/Tutorial_ABM_101.asp
Most useful tips in it:
To change the page to which an existing bookmark points: select the page you want to point to, then highlight the bookmark, right click, set destination.
To use a bookmark to open an external file such as Word or Excel doc
Create a new bookmark from the bookmark panel icon
Right click, select properties, Action, Open a file, Add, Ok
You can open webpages etc
You can open up specific pages in other pdfs
To make sub bookmarks you can drag it under the one you want to be parent
But you can also right click and cut the one or ones you want to move, then go to the parent, right click and Paste under Selected Bookmark
You can move bookmarks the same two ways.