Low water pressure to bath tub

I live in a condominium. The water was turned off for some plumbing repairs on the outside community grounds today. When the plumber turned the water back on to all the units I experienced very low water pressure to my downstairs bath tub on the hot and cold faucet sides, and low pressure to the upstairs bath tub faucet on the cold side. All other water faucets in the house remained with good water pressure. Prior to the outside plumbing work and the water being turned back on I had normal water pressure in the tubs. I took off the faucets and the cartridges look clear of debri. The water pressure coming out behind the faucets from the tub wall has full pressure. What might cause this low pressure to the faucets?

Like many folks, you are confusing "pressure" with "flow". That nitpicking aside, there is an obstruction in your pipes. I'm pretty sure the condo association should be able to require the plumber to return and locate the obstruction(s). In most condos, you are not allowed to work on plumbing or electrical yourself for liability reasons. While your problem isn't destroying or damaging your condo, there is a liability issue.