Detects whether a given data source is a direct child data source in the current scope, or whether it is a descendent data source.
Returns a boolean.
The required data-source identifies the data source to search for. Use data source path syntax to refer to data sources.
If the optional recursive is set to false (the default), the search is for direct children only. If recursive is true, the search is for children at any descendent level, for example, grandchildren.