I’ve got a file that is an RTF and says “FCP” underlined in blue. I mouse over it and it shows: Go to “Video Editing > Final Cut Pro”
When clicking on the link and choosing Edit Link it says: DEVONwiki_2 and clicking on FCP, takes me to my Final Cut Pro folder inside of DTPO.
I’m guessing I set it up as psuedo-TOC, but can’t figure out how I did, or how to add more ‘links’. 
Any suggestions? 
It is a WikiLink. Look at Preferences > Editing. Your settings in the “WikiLink” section of that panel might be Automatic and “Don’t Link to Groups” is not checked. Thus, when you type the name of a group into an RTF file a link to that group is automatically created. If “Don’t Link to Groups” is checked, then DT makes links to documents but not groups.
The Help file explains WikiLinks.
There used to be a script in the DEVONacademy section of DTech’s website that made an index of documents in this manner. I see that the link to that page is not active. Here’s the script, which depends on the “Automatic” preference for WikiLinks being checked:
-- Create index for selected items
-- Created by Christian Grunenberg on Wed Mar 15 2006.
-- Copyright (c) 2006. All rights reserved.
tell application "DEVONthink Pro"
try
set theSelection to the selection
if theSelection is {} then error "Please select some items."
set theIndex to ""
repeat with theRecord in theSelection
set theIndex to theIndex & (name of theRecord) & return
end repeat
set theRecord to item 1 of theSelection
if exists parent 1 of theRecord then
create record with {name:"Index", type:«constant Etyprtf », rich text:theIndex} in parent 1 of theRecord
else
create record with {name:"Index", type:«constant Etyprtf », rich text:theIndex}
end if
on error error_message number error_number
if the error_number is not -128 then
try
display alert "DEVONthink Pro" message error_message as warning
on error number error_number
if error_number is -1708 then display dialog error_message buttons {"OK"} default button 1
end try
end if
end try
end tell