Creating a new Multi Level Cascading Select List field.
To create a new Multi Level Cascading Select List field, go to Administration > Issues > Custom Fields > Add Custom Field > Advanced and select the Multi-Level Cascading Select field type:
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After you’ve added the values for the first level using the button + add Add option, To add new options as children of an existing one, click the Configure link and start adding add new options:
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It is possible to configure multiple levels:
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