Select the Module link in the top left banner then select the appropriate module name link.
Select the Forms tab.
Then select the Field List button "Create/Update Fields".
Select the field that you want to conditionally show or hide.
Select the Edit pencil icon on the field.
In the Display Condition Field enter custom js (Example- form.data.customSelectList11 === 'Part Shortage' in this case the field would only show if Part Shortage was selected in customSelectList11 field.)
Once you have entered all desired options click the Update button and then click Save on the Field List.