item with General category in the backend but with another category in the frontend

I'm sorry I did not explain myself well. The query or MySQL queries I want to obtain are those that identify the items that need to be displayed.

thtat depend what you want  .. we have many filter many function and join ... i don't understand sorry

I am interested in knowing the id of item, to hide articles with certain id. The articles that I want to hide are classified in a category, but in the frontend they are classified in a category that does not belong to the same category tree.

Menu item type: category blog

I have attached a screenshot of how it looks and one of the items I want to hide.

that a link to joomla view not flexicontent we can't provide support too joomla! we already have a big work for free with flexiontent .. sorry
but maybe you can do an override of you category view and display id ?

Thank you for your attention. I'll have to see what I can do.

Hello

i still think that you best option is to use
Flexicontent category / multi-category view

and work your configuration from there