All the examples for Salesforce show ways with the Napalli(Customer Support) Communities template to use the Search, Navigation, etc... items in a Custome Theme layout like here: https://developer.salesforce.com/docs/atlas.en-us.communities_dev.meta/communities_dev/communities_dev_example_structure.htm

<aura:component implements="forceCommunity:themeLayout" access="global" description="Sample Custom Theme Layout">
    <aura:attribute name="search" type="Aura.Component[]" required="false"/>
    <aura:attribute name="profileMenu" type="Aura.Component[]" required="false"/>
    <aura:attribute name="navBar" type="Aura.Component[]" required="false"/>
    <aura:attribute name="newHeader" type="Aura.Component[]" required="false"/>
    <div>
        <div class="searchRegion">
            {!v.search}
        </div>
        <div class="profileMenuRegion">
            {!v.profileMenu}
        </div>
        <div class="navigation">
            {!v.navBar}
        </div>
        <div class="newHeader">
            {!v.newHeader}
        </div>
        <div class="mainContentArea">
            {!v.body}
        </div>
    </div>
</aura:component>

We are using the Citizen Template and we want to create a CustomThemeLayout that uses the CompactHeader lightning component that is used on all our other pages. Is there a way to do this in my aura component with something like this.

<aura:component implements="forceCommunity:themeLayout" access="global" description="Sample Custom Theme Layout">
    <aura:attribute name="compactHeader" type="Aura.Component[]" required="false"/>
    <div>
        <div class="compactHeader">
            {!v.compactHeader}
        </div>
        <div class="mainContentArea">
            {!v.body}
        </div>
    </div>
</aura:component>

Doing it this way just defines a section called "compactHeader" it doesn't actually drop in the compactHeader Temaplate, so we're trying to find out what the syntax is to do this.