BFS

(function BFS(obj, lookingFor, maxFinds = 100, maxDuration = 3) {

	console.log('Traversing', obj, 'to find', lookingFor);

	let findCount = 0;
	let timedOut = false;
	let queue = [[obj, '']];

	setTimeout(() => (timedOut = true), maxDuration * 1000);

	BFS: for (let node, path; (obj = queue.shift()) && ([node, path] = obj); ) {

		for (let prop in node) {

			if (timedOut) { console.log('Timed out'); break BFS; }

			if (!{}.hasOwnProperty.call(node, prop) || (prop.indexOf('_') > -1)) { continue; }

			if (node[prop] instanceof Element) { continue; }

			if (node[prop] === lookingFor) {
				console.log('Found path:', path + '.' + prop);
				if (++findCount === maxFinds) { break BFS; }
			}

			if (['object', 'function'].includes(typeof node[prop])) {
				queue.push([node[prop], path + '.' + prop]);
			}
		}
	}
	console.log('Done traversing');
})({ a: 1 }, 1);