Database file location change on standby site after restore standby database
There are 2 ways you can fix this.


As @ramakant mentioned, SQL Server is using the default paths setup on the server. To change this, right click on the server in Object Explorer>Properties>Database Settings>Database Default Locations. Changing these values will automatically restore all databases to those directories unless different paths are specified.
You need to restore the database via a script, and that way you can specify where the files will be.
That will restore a database from a local location to the D: drive. Alter the script as required with regards to the locations.

RESTORE DATABASE [MyDatabase] FROM  
DISK = N'C:\Work\MyDatabase.bak' WITH  FILE = 1,  
MOVE N'MyDatabase' TO N'C:\MSSQL\Data\MyDatabase.mdf',  
MOVE N'MyDatabase_log' TO N'C:\MSSQL\Log\MyDatabase_log.ldf',  
NOUNLOAD,  STATS = 5
GO



More Info : RESTORE Statements (Transact-SQL)

Either one of these methods will work for you.