How do you search for nodes in a binary tree by level in PHP?

To search for nodes in a binary tree by level in PHP, you can use a breadth-first search (BFS) approach, typically implemented with a queue. Start by initializing a queue with the root node, then iteratively dequeue nodes, processing them level by level. For each node, enqueue its children until all nodes are visited. This method allows you to access nodes level by level efficiently.