I have a SSRS report with a Parameter that lets you choose the name of an employee. The report lists their Name, Number, User ID etc.
When you select a single employee, the filter on the Dataset works perfectly. However once you select two or more employee names, it only returns the first result. 

The parameter, Field, and Filter are text. 
The Filter is EmployeeName IN @EmployeeName

Any help is appreciated. 

Hi,

Try this.

=join(Parameters!EmployeeName.Value,",")  as a expression in dataset properties.

Tried this as well. Also tried it again just to make sure, Still no good. 

It's a filter, not part of the query.

Set your filter to be

Expression =Fields!field.Value
Operator IN
Value =JOIN(Parameters!param.Value,",")