@Pankaj I forgot mention the second step in my previous post,
you should define the attribute (that you are passing along with the
event) in the target component i.e. your component2 should have
'accountid' attribute defined in it
<aura:component implements="force:appHostable">
<aura:attribute name="accountid" type="String" />
<aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
Hello
</aura:component>
also, along with the above change in the controller of your target
component you will be able to access it in following
manner(note: not from the event but from the component)
doInit : function(component, event, helper) {
alert(component.get("v.accountid")) ;
},
Being said that, let me clarify that it is not recommended to use this event as, it is not yet documented in the developer guide and could be subject to any changes in the future releases with out any notice
Do confirm if the above approach worked for you.