Open Report filtering by multiselect field.

Open Report filtering by multiselect field.

I want to open a report using the following link

 "<a href='https://creator.zoho.com/" + zoho.appuri + "/#View:Task_Report?Staff=" + input.Staff + "'target='_blank'> View Tasks</a> ";

The report opens but shows no data available. I think the problem is that Task_Report.Staff is a multiselect field.

The following code is almost identical but uses State which is a single select field. It works as expected.
 "<a href='https://creator.zoho.com/" + zoho.appuri + "/#View:Task_Report?State=" + input.State + "'target='_blank'> View Tasks</a> ";

What is the syntax to open a report filtered by a multiselect field?