[SalesForce] how to use nested iteration in lightning and what is the alternative of apex:variable in lightning

I have a list of custom class objects. I am using aura:iteration to iterate the list. Now I want to show one of the variable of the class object which in itself is object.
For example in Salesforce Classic

<apex:repeat value="{!RequiredStoreActivities}" var="activity">
    <apex:variable value="{!activity.StoreActivityCategory}" var="activityCategory" />
    <div >
        <span ></span>
        <apex:outputText value="{!activityCategory.Store_Activity_Category__c}" />

    <div >
        <ul >
            <apex:repeat value="{!activity.StoreActivities}" var="storeActivity">
                    <apex:outputText value="{!storeActivity.Name}" />

Where RequiredStoreActivities is a class

public class RequiredStoreActivity{

  public final Store_Visit_Activity_Category__c StoreActivityCategory {get; private set;}
  public List<Store_Activity__c> StoreActivities {get; set;}

I have to implement the same in lightning. Can somebody help me in it
till now I am able to code the below code

<aura:iteration items="{!v.RequiredStoreActivity}" var="st">
    <aura:renderIf isTrue="{!v.showActivity1}">
        <c:StoreActCategory storeActivityCategory="{!st.StoreActivityCategory}"/> 

Since we cannot use apex:iteration inside apex:iteration. I have passed the value to a component. But on the another component the value is getting undefined

Best Answer

Just tried aura:iteration inside the aura:iteration and works great .Here is a sample that clearly shows no harm in using nested aura:iterations

<aura:component >

<aura:attribute name="arrvals" type="integer[]" default="1,2,3,4,5"/>    

   <aura:iteration var="num" items="{!v.arrvals}" aura:id="ipv" indexVar="index">
     <aura:iteration var="num1" items="{!v.arrvals}" aura:id="ip12" indexVar="index">

What you might be missing from my opinion is below

Make sure All your inner varibales are annotated @Aura Enabled

The equivalent of apex:var in lightning is aura:attribute .You can declare aura:attribute to store and retrieve values from same as you do for apex:variable in Visualforce