How to display node's taxonomy child items in node using views for multiple parents
The goal was to display child items for multiple taxonomy terms of the node in a node's field using views.

Solution:




Create content type with:


Taxonomy term field (multiple values) - it's for parent items
Views field - it's for displaying child items for ALL parents

Make standard taxonomy tree view with ajacency model (search google)


Add a contextual filter with parent term ID 


Provide default value
Taxonomy term ID from the URL
filter to items that share any term
When the filter value IS available or a default is provided


Specify validation criteria - taxonomy term ID
Filter value type - Ternm IDs separated by , or +



Edit view field of previously created content type 


Select the view created as a default value for this field
From placeholder list select [node:field_bla_bla] (that's taxonomy parent field in the node) as an argument passed to default value