Your company operates a 3-tier architecture hosted on Google Cloud's Compute Engine. Each tier is managed with its own service account that is linked to all instances within that specific tier. To ensure proper functionality and seamless communication between the different tiers, you need to configure the network to allow communication over TCP port 8080. The communication requirements are as follows:

• Instances in tier #1 must communicate with instances in tier #2.
• Instances in tier #2 must communicate with instances in tier #3.

What steps should you take to accomplish this configuration?