Unfortunately it doesn't seem like there's any support for multiple monuments on custom maps. 
And you'll have to find out for yourself which of the multiple monuments that belongs to the CCTV codes

Large Oilrig:

OILRIG2L5
OILRIG2L6A
OILRIG2L6B
OILRIG2L6C
OILRIG2L6D
OILRIG2L2
OILRIG2L1
OILRIG2L4
OILRIG2L3A
OILRIG2L3B
OILRIG2EXHAUST
OILRIG2DOCK
OILRIG2HELI

Small Oilrig:

OILRIG1L1
OULRIG1L2
OILRIG1L3
OILRIG1HELI

Dome:

DOMETOP
DOME1

​Outpost:

COMPOUNDSTREET
COMPOUNDCHILL
COMPOUNDMUSIC
COMPOUNDCRUDE

Bandit Camp:

CASINO 
TOWNWEAPONS

Airfield:

AIRFIELDGARAGE