obsidian://vault/vaultname, where vaultname is the name of the folder of the vault.obsidian://vault/vaultname/path/to/file.obsidian:///absolute/path/to/file or on Windows obsidian:///C:\path\to\file (forward slash also works). This will open the file in the most nested vault that's capable of opening this file.Exec=obsidian %u. Details see here.