Function resolve_field_reference 

pub fn resolve_field_reference<'a>(
    expression: &str,
    current_path: &[String],
    row_keys: &[usize],
    form_data: &'a Value,
) -> &'a Value

Resolve a field-reference expression to its value (JS resolveFieldReference): .x / ..x relatives with a row as one level, a dotted path from the root and a bare name resolved as .name.