We had the carpet in our master bath removed and ceramic tile installed. Since that time, about 4 years ago, the hot water pressure in the master tub has been low. The sinks work fine and the tub cold pressure is great. But the hot water pressure only comes out about 1/3 of before. Takes forever to fill the tub up even half way. I don't know if the tile installation has anything to do with it; but I remember that it worked fine before that time. Please help.

Please excuse the delay in my answer. Sounds like you have some crud that's clogging the inlet ports of your cartridge in your valve.
Shut off the water, open up the valve and clean and check the inlet ports. Before you reassemble turn the hot water on to flush out the hot water supply. To tell you more I'd need the brand name of the faucet and it's age. Regards, Tom