Welcome.
Most times when one side of the Capacitor goes to Ground then it's for DeCoupling on some DC line, and most of the time it will be OK to just leave it off or replace it with some typical value, 0.01, 0.1 or 1uF and it will be fine.
If neither end goes to Ground then it's for Coupling, and should be replace with the same value.
In both cases, replacing it with the same value is what's best, but for DeCoupling caps that can be fudged to an extent.