gistfile1.txt

You can do it with a simple template object. Here's an example:

contentMenu = TYPO3.TypoScript:Template {
	templatePath = 'resource://Moc.Net/Private/Templates/TypoScriptObjects/ContentMenu.html'
	items = ${q(node).children('[instanceof TYPO3.Neos:ContentCollection]').children('[instanceof Moc.Net:SectionGrid][showInContentMenu = true]')}
}

{namespace moc=Moc\Net\ViewHelpers}
<f:if condition="{items}">
	<ul>
		<f:for each="{items}" as="item">
			<li>
				<a href="#{item.properties.header -> moc:slugify()}" class="content-menu-item">{item.properties.header -> f:format.stripTags()}</a>
			</li>
		</f:for>
	</ul>
</f:if>

We've used a slugify view helper to turn the title into an id which we also use for the content elements we're creating a menu for. You can also just use the identifier (usually something like 1a490c12-c30e-cab2-de08-03096cddf7ed) by using {item -> f:format.identifier()} and then make sure that is also done to your content elements. That can be done using the attributes for the content wrapping. Example:

prototype(TYPO3.Neos:Content) {
	attributes.id = ${node.identifier}
}

or the name (usually something like node52697bdfee199)

prototype(TYPO3.Neos:Content) {
	attributes.id = ${node.name}
}