<aura:registerEvent name="testEventFired" type="c:testevent"/>
 <aura:handler name="testEventFired" event="c:testevent" action="{!c.func}"/>
 <force:inputfield aura:id="Name" value="{!v.objectfieldbinding}" change="{!e.testEventFired}"/>
  testevent is component event
  2:
 <force:inputfield aura:id="Name" value="{!v.objectfieldbinding}"/>
   <aura:handler name="change" value="{!v.name}" action="{!c.func}"/>`

<aura:registerEvent name="componentEventFired" type="c:Callevent"/>
<aura:attribute name="obj" type="csutomobjecttype" default="{ 'sobjectType': 'customobject' }"/>
<force:inputfield aura:id="Account" value="{!v.obj.Accountlookupfield}" change="{!c.evac}"/>
<aura:handler name="componentEventFired" event="c:Callevent" action="{!c.trigaction}"/>
event:
<aura:event type="Component" description="Event template">
<aura:attribute name="display" type="object"/>
</aura:event>
controller Js:
evac: function(component,event)
          {
            var  evva=component.find("Account").get("v.value");
            var compEvents = component.getEvent("componentEventFired");
            compEvents.setParams({ "display" : evva });
            compEvents.fire();

           },
        trigaction : function(component, event) {
        var context = event.getParam("display");
        var atmaction=component.get("c.getatm");
        atmaction.setParams({
            atr : context
        });
           atmaction.setCallback(this,function(a){
            //get the response state
            var state = a.getState();
            //check if result is successfull
            if(state == "SUCCESS"){
                component.set("v.at",a.getReturnValue());
                component.set("v.edit",true);
                alert('Success');
            } else if(state == "ERROR"){
                alert('Error in calling server side action');
            }
        });
        $A.enqueueAction(atmaction);
      }
})
Apex class:
public Id atr {get;set;}
@AuraEnabled
Public static List<AccountTeammember> getatm(string atr){
            List<AccountTeammember> atm = new List<AccountTeammember>();
            atm=[SELECT TeamMemberRole,UserId FROM AccountTeamMember where AccountId =:atr ];
    return atm;
    }
}

<aura:application controller="AccountController" extends="force:slds">
   <aura:attribute name="contact" type="Contact"
               default="{ 'sobjectType': 'Contact' }"/>
   <force:inputField aura:id="accountLookup"
                 value="{!v.contact.AccountId}" change="{!c.inputChanged}"/>
</aura:application>

({
    inputChanged : function(cmp, event, helper) {
        console.log('changed')
    },
})