This feature allows you to designate a drop-down choice field as a decision field which, depending on what choice is selected by the user, displays a pop-up window with fields that are specific to that choice. For example, a field called Error Message can be displayed in a pop-up window only if the user selects Software Error from a Problem Type field.
Before you begin:
To designate the decision field:
GO.

Select a decision field for the pop-up window
GO. The
top half of the next page allows you to define the dependent fields.
If your decision field has three possible values, a choice box for each
value is displayed, each choice box containing a list of all project fields.
Configure field dependencies
The bottom section of this page allows you to define the behavior of these fields under special circumstances. That is, the choice you make in the bottom section controls what happens when a user changes a choice in the decision field after already entering data into the dependent fields.
This next step is optional.
For
additional drop-down fields found in the project (not including the main
decision field), a series of choice boxes for each of your possible values
is displayed in the bottom half of the page. Continuing
with the above example, for each of your three key values in the decision
field there is a choice box for each choice field in the project.
If there are four choice fields defined (other than the decision field)
in the project, there are twelve choice boxes (four for each of the three
decision values).
By default, all values are selected. You can optionally use one or
more of the fields displayed here to pick different values of the same
choice field for the different values of the decision field. Only
de-select the values for a particular set of fields that you want to limit
(use the CTRL key to highlight multiple fields). Otherwise,
do no de-select any values.
All other values for Version number for each of the three choices above should be de-selected. All other values for any other fields should remain selected.
Configure Field Dependencies, part2
“GO”.Multiple decision fields can be created using the method above.
Now when you create an Issue, the Issue Information section contains the decision field. When a value is selected in a decision field, a pop-up box is displayed, containing the additional dependent fields for that value. Using our example, if Software is chosen, Version number is displayed with the only options being 97 and 2000. In addition, any other fields associated with Software (chosen in the top section of the Dependencies screen) are displayed.
Different fields will appear in the pop-up window depending on the "Problem Type"