Go to Jira Administration > Issues.
Under FIELDS, select Custom fields.
Find your existing Add Another field and click on Configure.
In the 'Add-Another Configuration' section, click the 'Edit Configuration' link.
Fill in required configuration fields in order Add Another field to work.
Field Description: description text to be shown above the Add Another field.
Destination Issue Type: the type of issue that will be linked to the issues created via Add Another field.
Source to Destination Link Type: the type of issue link that will be created between the current issue and the issues creating from the Add Another field grid.
Default Project: The default project that will be set to the issues created via "Add Another". (Can be override by the user if “Project“ field is selected to be one of the fields in Add Another configuration)
Show as Grid:
If turned ON, the field will be shown as grid with maximum of 4 Fields
If turned OFF, the field will be shown as a sub-form inside the Jira create issue screen with unlimited number of fields
Field: fields to display in your Add Another field. see Supported Fields.