How to create a 3x level deep term menue?

[Rar9]

How to build a 3x level menue with terms that can be moved in order/hierarchy? Each term will have multiple fields.

My guess array in some relationship, but Video would be much better for understanding.

This is 3 levels but is missing user friendliness,
This is especially true more than a name field is required.

if each term requires images and multi richtext fields need to be added everything will be impossible to edit.

Perhaps there is a better way?

{ name:"level1", type:"array", fields:[ {name:"name",type:"text"}, {name:"level2",type:"array", fields:[ {name:"name",type:"text"}, {name:"level3",type:"array", fields:[{name:"text",type:"text"}]} ]}, ] },