When hierarchical data is retrieved from a REST endpoint, it's really cumbersome to get that data into a dimension. Imagine, your JSON data has the following hierarchy:
Legal entity > Function Area > Cost Center
Naturally you'd configure your JSON extract in a way, that you get all the cost centers, so loop expression would be e.g.
$data[0].legalentity[*].functionarea[*].costcenter
The problem is, that you will not be able to retrieve the information about function area and legal entity that way, because you cannot get information about parent node through JSON path expression in Jedox.
Therefore, to retrieve the full hierarchy you first have to extract all legal entities, then use a loop to retrieve all function areas per legal entities, then use another loop to retrieve all cost centers per function area.
This is a lot of ETL footprint considering it's a common use case.
Possible solutions:
a) JSON hierarchy extract
b) syntax to retrieve information about parent nodes as part of the JSON path expression
