Run water in tub drains. Fill tub does not drain
S L O W L Y drains. Used plunger and snake still drains slowly hours.

Snake from the tub waste and overflow, (see image). Unscrew and remove the overflow plate, (The one with the drain lever) and pull out the tub stopper. You now have a clear shot at the trap. The way you were going in through the drain it ran you square into a tee that you can't get around. Now feed the cable (1/4" best or 3/3" with a small tip. You can rent a Ridged K50 sink cable.) About 2' down you will run into the bend of the trap. Crank and push at the same time to work around it. Your blockage will be found in the lateral pipe going to the stack. You shouldn't have to put out more then 10 or 12 feet. I have found tub and shower clogs to be mostly hair and the worm should auger into it and pull it back, good luck.

John