Connections
Group 1
Words that contain the sound FOUR - Before, Guffaw, Metaphor, Semaphore
Group 2
Words that form movie titles when combined with the number EIGHT - Eight Below, 8 Mile, 8MM, Super 8
Group 3
Words that mean FIFTEEN - F (hexadecimal), Quince (Spanish), XV (Roman numerals), Commodore (Cockney rhyming slang) (credit to BeastlyGerbil for spotting this in the comments)
Group 4
Things that are composed of SIXTEEN parts - Myers-Briggs (16 categories), SnesSNES (16-bit), Pound (16 ounces), Pool (16 balls)
Group 5
Words which are TWENTY-THREE in an ordering - Harrison (23rd U.S. President), Isaiah (23rd book of the Bible), V (23rd chemical symbol of the periodic table), Whiskey (23rd letter of the Nato PhoneticNATO phonetic alphabet),
Group 6
Words associated with the number FORTY-TWO - Asterisk (decimal code), Czechoslovakia (calling code), Loire (France department number), Robinson (famous for wearing number 42)
So the categories are
4, 8, 15, 16, 23, 42
And we recognise these as being
The six numbers that reappear consistently in the TV Showshow LostLost
So the four-letter word must be
Lost
Title
"Off the beaten track" means in an isolated place. In the TV show Lost, the characters are trapped on a mysterious remote island when their plane crashes.