Appropriate way to get the item within a content block?

I have a little component like this.

  // ... not important
  +EasySearch.Each index=index
    +Template.contentBlock data=currentData

I am trying to register some functions on this. Eg:

infiniteScroll() {
  let containerSize = $(this.firstNode()).parent().height();
  // want to get the size of each thing in the content block here
insertDOMElement() {
  // only want to call within the template.contentBlock objects

What is the appropriate way to do this?