gistfile1.txt

function drawNestedSetsTree(data, node) {
	var subItems = [],
		itemsRelations = [],
		subArr = [],
		dataArr = [],
		mainArray = [];

	// Find the deepest elements
	data.forEach(({ title, left, right }) => {
		if (right - left === 1) {
			subItems.push({
				title: title,
				left: left,
				right: right
			});
		}
	});

	// Find all parents of the deepest elements and push them into array
	for (var index in subItems) {
		var relationsArray = [subItems[index]];
		getRelations(subItems[index], relationsArray);
		relationsArray = relationsArray.reverse();
		subArr.push(relationsArray);
	}

	// Create related array with sorted unique elements
	for (var itemIndex in subArr) {
		var tempSubArray = subArr[itemIndex];
		for (var subItemIndex in tempSubArray) {
			var hasItem = dataArr.find(function(itemObj) {
				var result = itemObj.title === tempSubArray[subItemIndex].title;
				return result;
			});
			if (!hasItem) {
				dataArr.push({
					title: tempSubArray[subItemIndex].title,
					deph: subItemIndex,
					from: tempSubArray[subItemIndex - 1] ? tempSubArray[subItemIndex - 1].title : false,
					children: []
				});
			}
		}
	}

	// Create main array with structured unique elements and its children
	for (var j in dataArr) {
		var elem = dataArr[j];
		if (!elem.from) {
			mainArray.push(elem);
		}
		pasteChildren(elem);
	}

	// Find children and push into corresponding item in the main array
	function pasteChildren(parentElem) {
		var childElems = [];
		for (var i in dataArr) {
			if (parentElem.title === dataArr[i].from) {
				childElems.push(dataArr[i]);
			}
		}
		if (childElems.length) {
			parentElem.children = childElems;
		}
	}

	// Build chain of parents
	function getRelations(item, array) {
		function findParent(index) {
			var itemParent = data.find(function(itemObj) {
				return itemObj.left === index;
			});
			if (!itemParent) {
				if (index > 0) {
					return findParent(--index);
				} else {
					return array;
				}
			} else {
				if (itemParent.right > item.right) {
					array.push(itemParent);
					getRelations(itemParent, array);
				} else {
					if (index > 0) {
						return findParent(--index);
					} else {
						return array;
					}
				}
			}
		}
		findParent(item.left - 1);
		return array;
	}

	// Created DOM tree using main array
	function createHtml(array, place) {
		var ul = document.createElement('ul');
		for (var finalIndex in array) {
			var li = document.createElement('li');
			li.textContent = array[finalIndex].title;
			ul.appendChild(li);

			if (array[finalIndex].children.length) {
				createHtml(array[finalIndex].children, li);
			}
		}
		place.appendChild(ul);
	}
	createHtml(mainArray, node);
}


if (typeof module !== 'undefined') {
	module.exports = drawNestedSetsTree;
}