From the property definition
List<String> projects = []
the elements of projects are Strings, that's why you can not query projects.name
, which is not known to GORM.
And in your last comment, the value in a projects instance "projects": { "0": { "description": "123", "name": "cms" }, "1": { "description": "cms", "name": "codebucks" } }
looks like a Map, where the project number is the key and a inner map containing name and description is the value, rather than a List.
To serve your purpose, you need to modify your domain class definition to ensure consistency between your model and data.