Allow querying by root owner

[shifuma]

TLDR: There are times when it would be nice to get deeply nested entries, without needing to go through all levels: craft.entries().field('nestedMatrixField').rootOwner(entry).all()

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Some more information on my setup:

• Events have various relation and other fields (category, date, day of the week etc)
• Companies - a Matrix field on Events
• Presentations - a Matrix field on Companies

On a company's page, I am listing all of their presentations. However, I want to then filter those based on fields on Events. For example, from Company A's page, I want to see all of their presentations made at Events on a Saturday. That's where I thought this would be perfect.

-- `companies/_entry.twg` --
{% set events = craft.entries().section('events').dayOfTheWeek('Saturday').ids()
{% set presentations = craft.entries().field('presentations').rootOwnerId(events).all() %}

[shifuma]

Related: #15534

[rungta]

+1 for this feature. Example use case: we have a data model for storing a book’s table of contents, where a book contains multiple chapters and these chapters are grouped in sub-sections. The sub-sections can also be grouped together inside a parent sub-section, infinitely. So we end up with a structure such as:

Book One (root entry):

• Contents (matrix field)
  • Sub-section A (matrix field)
    • Chapter A.1
    • Chapter A.2
  • Sub-section B (matrix field)
    • Sub-section B.1 (matrix field)
      • Chapter B.1.1
      • Chapter B.1.1
    • Sub-section B.2 (matrix field)
      • Sub-section B.2.1 (matrix field)
      • Sub-section B.2.2 (matrix field)
        • Chapter B.2.2.1

Note that Books and Chapters are both separate sections.

In order to query all chapters of a book, would be great to write craft.entries.type('chapters').rootOwner(bookEntry)