Should be all one piece from filter on tank end, through hole in tank wall to carb. Fish the tank end out with a hooked wire through the filler hole for inspection. Take the filter off end and pressure test hose or just pull it out and replace. Use longer length of new, taper the end for a couple of inches so it goes through the hole easily, cut off tapered end to install filter. Or just put length from carb to can with gas for testing, when it runs that way, connect to line in saw and try again to see if it still runs.
That bolt/stud thing is likely a problem, should be sealed up tight. Would never run with that big hole open.