<aura:iteration items="{!v.selectedFilters}" var="filter" indexVar="filterIndex">
   <li class="slds-pill slds-m-right--xxx-small" >
     <a href="javascript:void(0);" class="slds-pill__label" title="Full pill label verbiage mirrored here">{!filter.displayValue}</a>
     <lightning:buttonIcon iconName="utility:close" alternativeText="close" variant="bare" onclick="{!c.resetFilter}" value="{!filterIndex}"/>
  </li>
</aura:iteration>

resetFilter : function(component,event,helper) {
    console.log(event.currentTarget);
    console.log(event.target);
}

<aura:component >
  <aura:attribute name="label" type="string"/>
  <aura:attribute name="value" type="object"/>
  <aura:registerEvent name="onclick" type="c:evtDOMEvent"/>

  <a href="javascript:void(0);" class="slds-pill__label" title="Full pill label verbiage mirrored here">{!v.label}</a>
  <lightning:buttonIcon iconName="utility:close" alternativeText="close" variant="bare" onclick="{!c.triggerOnClickEvent}"/>
</aura:component>

({
   triggerOnClickEvent : function(component, event, helper) {
     component.getEvent("onclick").fire();
   }
})

<aura:iteration items="{!v.selectedFilters}" var="filter" indexVar="filterIndex">
    <li class="slds-pill slds-m-right--xxx-small" >
       <c:uiPill label="{!filter.displayValue}" onclick="{!c.resetFilter}" value="{!filterIndex}"/>
   </li>
 </aura:iteration>

resetFilter : function(component,event,helper) {
    console.log(event.getSource().get("v.value"));
},

<lightning:button aura:id="button" variant="brand" label="Submit" onclick="{! c.getMyId }"/>

getMyId : function(component, event, helper) {
    console.log(event.getSource().getLocalId());
}

<aura:component>

    <aura:attribute name="press" type="Aura.Action" access="global" description="JS controller action to perform when button pressed"/>
    <aura:attribute name="value" type="String" access="global" description="Button value"/>

    <button onclick="{!v.press}" value="{!v.value}">
       <!-- manage your styles here with some input parameters -->
    </button>

</aura:component>

<c:Button value="yourvaluehere" press="{!c.onPushTheButton}" />

onPushTheButton : function(component, event, helper) {
    var Val = event.target.value;
    // You'll get 'yourvaluehere' in Val, do whatever u need with it :)
}

<aura:component>

    <aura:attribute name="press" type="Aura.Action" access="global" description="JS controller action to perform when button pressed"/>
    <aura:attribute name="value" type="String" access="global" description="Button value"/>

    <span onclick="{!v.press}" value="{!v.value}">
       {!v.body}
    </span>

</aura:component>

<c:Button value="yourvaluehere" press="{!c.onPushTheButton}">
     <p style="background-color:green;">MyButton,images,whatever u want</p>
</c:Button>

<lightning:button class="action-btns" value="yourValue" variant="neutral" label="something" onclick="{! c.handleAction }">

handleAction : function(component, event, helper) {
        var btnValue = event.getSource().get("v.value");
    }