Parent

Purpose: allows you to create descendants for records, thereby organizing a tree.
Field type in SQL table: int

Additional parameters:

name_field
Purpose: when displaying a list of possible model values, a field named 'name' is searched for; if this field is missing, then you must specify the field that will be used as a named field
Possible values: field name, for example 'first_name', 'label', 'date'
Default: 'name'

max_depth
Purpose: maximum nesting depth, number of possible tree sublevels
Possible values: positive integer
Default: null

parent_for
Purpose: organizes a connection with another model based on the catalog principle -> catalog -> catalog -> product. The current model has nested subsections that may contain records from another model.

Possible values: model name, e.g. 'Products', 'Topics'
Default: null

show_parent
Purpose: additionally shows the parent name for the field values 
Possible values: true, false
Default: false

Examples:

['Parent section', 'parent', 'parent']

['Section', 'parent', 'section', ['name_field' => 'title']]

['Catalog', 'parent', 'catalog', ['parent_for' => 'Products',
                                  'max_depth' => 3,
                                  'show_parent' => true]]