Install Conversations app by going to Apps Marketplace.

Apps Marketplace

The app consists of an additional Item View. Once installed, you can add it by clicking on any item on the board to open side menu, then click 'Add View' button. Search for Conversations and click 'Add Widget'.

Add Item View

First time use

After installation you will get new tab in item view, click 'Conversations' tab to see updates from all linked items.

Conversations Item View.

Click settings to configure what updates should be included.

Conversations Item View Settings.