We have a SSRS report which contains a dataset which has an ID and NAME field, then a parameter was created and set its value to ID from dataset and Label to NAME of dataset. The label can be displayed in preview report and select it, but the selected parameter label display also needs to show on the report, if just use Parameters!Parametername.Value, it just shows the value or ID directly. So the correct way is as below.
Case when the parameter is Single Value :
Case when the parameter is Multi Values :