How to add dynamic select lists to a form

My council services provides the ability to add a dynamic select list to a form. The dynamic select lists allows an answer to be pre configured so that once a specific answer has been selected for the parent item, only certain answer items will be available to choose from for the dynamic select list. 

Please note, the dynamic select list is for the WEB only, you will not be able to use the dynamic select list on the mobile devices. 

Firstly you will need to go to Administration->Forms Builder , once opened you will then need to find the specific form which you would like to add the dynamic select list to. 

Once you have opened up your form, you will need to add a new item which will be a select list. (This item will be the parent item for the dynamic select list). After adding the select list, you will need to add answer values for the item. 

Now that you have added the parent item select list, you can now add the dynamic select list. This can be done by adding a new item which will have the item type "Select list- Dynamic(Web only)".  Below item type, you will find "Parent Item" , this will be the name of the select list you created. Once this has been selected you can begin adding your answers. 

As you can see, when adding the answer in the answer section,  parent answer is one of the fields. This is linked to the normal select list you have created. As you can see for example, "Mobile" has been entered in the parent answer field which means that if mobile is selected in the normal select list,  then only the answer 'Phil" will be available to select in the dynamic select list.