Navigate to your Jira administration - Issues - Custom Fields - Add custom field
Select a field type Multi Level Cascade Field
Set the field name and a description and define its context, just like you do when creating other custom fields.
Make sure that you limit the context of the custom field to the projects that are effectively using the custom field.
Configure the Multi Cascade
You can configure the field through the standard custom field configuration of JIRA. All configuration details for a specific multi cascade need to be entered in the "Multi Level Cascade Field" configuration of a custom field.
By default, a new Multi Level Cascade Field is filled with a sample configuration. You can override or change this configuration to match it to your needs. Next chapters will explain in detail how to configure a Multi Cascade.
Format of the configuration
The Multi Cascade is using the standard java properties file format to read and interpret the properties.
Each line stores a single property
Each property is stored as a pair or strings separated by a '=' For instance,
mc.levels = issuetype, user, issue
level.user.query = select user_key from app_user
The first part is the key, the second part is the value
the key can be multilevel. For instance, level.user.query has 3 levels
If the first character on a line is the number sign (#), all the remaining text on that line is interpreted as a comment
The order of properties is not important. For clarity and maintenance, it is best to group similar properties together.