Hi,
I am using following script in Related Link UI Action on Incident Form:
function showMyForm(){
//Get the table name and sys_id of the record
var tableName = g_form.getTableName();
var sysID = g_form.getUniqueValue();
//Create and open the dialog form
var dialog = new GlideDialogForm(‘Related Lists’, tableName); //Provide dialog title and table name
dialog.setSysID(sysID); //Pass in sys_id to edit existing record, -1 to create new record
dialog.addParm(‘sysparm_view’, ‘related_list’); //Specify a form view