Depending on how much data you'll have in your database, you can do 1 of the following;
Either you filter on the datasource:
bsEmployee.DataSource.Filter = "AcolumnName like 'value'";
or you will make a sql query and add that to your TableAdapter, so that you will not load too much data into your application. (To add a parameterzied query go to DataSet designer,right click the TableAdapter you want to modify, and add a query. in the where statement you can write something like this " WHERE (columnName = @VariableName)"
taEmployee.FillByDepartment(datasetName.dataTableName, departmentNameVariable);