There are two options to create a dependency: From the list of jobs or using the Duplicate button in a job.
From the list of jobs
To create a dependency between two jobs, simply drag and drop one job into another.
The system will ask you what you would like to do:
If you choose to create a dependency, you will see that one job is the parent job, and the other one (the Revision in the screenshot below) is a "sub-job" depending on the main job.
To "break" a dependency, you have two options:
If you want the sub-job to stay in the group and be placed at the same level as the other "parent jobs" in the group, you have to drag and drop it at the top of the list in the group details. In the screenshot above, this would be just under the "Name" column title.
If you want to remove the job from the group, you have to use the corresponding icon (broken chain) in the group details. When there is only one job left in a group, the group is deleted (but not the job of course!).
Using the Duplicate button
In your jobs, you can use the Duplicate button to add the duplicated job to a new group, to add it to an existing group or to create a dependency.
If you choose to duplicate the job and create a new group, you will see, once in the duplicated job (on the left under the job name), that a group has been created along with the duplicated job (you can edit the name and the color of the group by clicking on it).
If you choose to duplicate the job and add it to the group, the job will be added to the group of the job you are duplicating.
If you choose to duplicate the job and create a dependency, the duplicated job will become a dependency of the job you're duplicating.