Hi, so the rubber piece that holds the leg hose is stitched to the uniform leg.
The hose itself is likely just clipped to the belt as many of us do ourselves. Either a carabiner or clip with a D- ring through the tue or an insert into the hose.
https://www.theghostbustersreferencelibrary.com is a very useful site for detailed photos, but nothing showing the backs of the belts.