As I will have one parent and more than one child channels we will have to create more repositories and more channels. For example I will add spacewalk channel to be a child channel, so here are steps to create child channel. As for parent channel you have to create first repository.

Channels -> Manage Software Channels -> Manage Repositories -> Create Repository

You should define Repository label and give a URL where packages are located. Click on Create Repository button.

Now create child channel

Channels -> Manage Software Channels -> Create Channel

You should define channel name, channel label, as this will be parent channel use one you crated in step before, checksum type and Channel summary. Click on Create channel button.

Steps for connecting repository and channel are same as described in last step.