How do I fix a dripping tub faucet. I have the faucet apart a couple of time but not the guts of it?

To help we must first know the brand name, type, (one handle or two knobs) and its approximate age. Replacing the cartridge and flushing out the supplies usually takes care of the drip. Plese send us all the details you have.
Thanks, Tom

It has 2 knobs and faucet in the middle