openupm add com.ivysola.uquery

or paste this into manifest.json

"com.ivysola.uquery": "https://github.com/0xF6/UQuery.git?path=src/",

/* graph of game objects
  %scene_root% |
        - Canvas |
            - Layout |
                - Header |
                    - Title | <UIText>
*/

var result = UQuery.SelectByPath<UIText>("Canvas>Layout>Header>Title[UIText]");
result // UIText component

var result = UQuery.SelectByPath<GameObject>("Canvas>Layout>ButtonGroup");
result // GameObject 'ButtonGroup'

/*
%root% |
    - Canvas |
        - Layout |
            - Header |
                - Title1
            - Header |
                - Title2
            - Header |
                - Title3
            - Header |
                - Title4
*/

var result = UQuery.SelectByPath<UIText>("Canvas>Layout>Header:(2)>Title3");
result // GameObject 'Title3'

• Light Documentation
• Samples
• Validate IL2CPP Target
• Directives for MORELINQ & UNITY_LINQ
• Support querying by tag\layout (?)
• Aliases in Query Path
• Strong validation path format
• Additional exceptions types
• Query cache system
• Access child (same names) by index

So, the code of this library uses C# 8.0 version, upm puts the source code in its pure form, and unity compiles it with its internal compiler - so the minimum supported version of the package is 2020.2. if you want to use this library on older versions of the engine, the compiled library (built in Plugins) can also work on version 2019.* or you can use C# Custom compiler for set-up your 2019.* unity to you to compile C# 8.0 in packages asmdef.