If it’s hoses inside conduits you should have water coming up from inside the conduit that houses the leaking line
This^ plus, the reason for these manifolds is to enable shutting down one fixture at a time to allow service or repair in an emergency. (Also to reduce the lengths of full diameter pipes). Hopefully the manifolds are accessible and have individual valving. Then it is a process of elimination. Be sure it is water lines and not radiant heat.
