When you're in the build config screen and go to the build chain tab, you see all instances/rows of the chain that passed this build config. You also see the following build configs in the chain which have not been triggered yet. You can trigger the next build config in the chain by pressing "run". The build config will be started by this, but as a side effect, you'll be taken to that build config's screen. The current instance of the chain will also be collapsed.
From a continuous delivery perspective, I find this behaviour very confusing. You certainly don't expect to be taken to another build config when you press "run". I guess there was a good reason to design TC like this, but when using build chains to model continuous delivery pipelines, this is not helpful. Can it be switched off somehow?
To go one step further, I'd argue that for CD, the concept of tying a build chain to a particular build config is not a good idea. It should be a separate entity with a separate screen in the UI, not a tab of a build config.
A build chain could have a name/ID and then you'd explicitly state that it's built up of this build config, followed by this, etc. I understand that the concept of build chains does not equal that of a build pipeline in continuous delivery.